Aquaponics - Houston we have a go.

Well I got the float switch pump in today and took several pics so this will probably not be a long post but more visual. I clamped the float switch to a piece of PVC, then zip tied it to the sumptank barrel by drilling two small holes in the side of the sumptank and threading the zip tie through them.

The float switch has a power adapter that plugs into my power strip, then the pump gets plugged into the float switch's power adapter, when the water in the tank reaches the level I want, it closes the relay and sends power to the pump until the water level lowers beneath the threshold again. I can easily move the float up and down the PVC pipe to adjust the water level.

 It's not rock solid yet but I wanted to make sure everything worked first. It has been running for about 3 hours now with no sign of any problems, at least not to do with the pump. I still have to fine tune the rate each bed gets flooded by using the ball valve but they do all flood completely within the 15 minute pump cycle. I will focus for the next few days on cleaning the filters of the pumps out a couple of times to see if I can clear up the water some, I like being able to see the bottom of the fish tank. I am not sure if I should be filtering out the solid waste or simply letting it get pumped into the grow beds but I will hit up the Aquaponics forum over at http://aquaponicscommunity.com/forum
to see what the consensus says. That forum is a plethora of good info and if you are going to try aquaponics I would highly recommend it. It is well moderated and I have always gotten responses. Ok, so some pics, some will be self explanatory.

Aquaponics - Hurdles

Been a pretty long time since my last post, mainly because I ran into some issues and had to re-evaluate my plan. 

First off, I ditched the loop siphons, just couldn't get them to work correctly. It really irks me that I couldn't figure out why but I tried NUMEROUS variations, even making loops out of hard PVC which I thought was going to work but did not.

 I think it has to do with the barrels not holding enough water to force the siphon to kick in. I say this because of one experiment I did where I had all the water flow from my pump coming into one bed instead of divided into the four beds I have. When I had all the water flooding one bed, the siphon kicked in fine. Now when I hooked all four beds up , they filled up and the water started draining back out at exactly the rate it was coming in at and the siphon never kicked on. IF, however, I smacked the siphon loop a couple of times, it would kick on and start the siphon and drain correctly down to the bottom. Call me crazy but sitting on a stool smacking PVC all day just wasn't my idea of fun.

 So, we move on to another plan. My next plan was to put a cheap timer on the pump and have it run for 15 on 15 off. I have installed an overflow tube at the top of the fishtank. My thinking was the water would drain out the tube at the same rate that it was being pumped in by the pump line, but it did not. The pump moved more water into the tank than was being drained out so the water level rose to over the top of the drain tube. I  suppose I would have installed a bigger drain line or multiples to make sure the water ran out as fast as it came in but honestly I got distracted by my next idea: using two pumps. THIS WAS A BAD IDEA ALL THE WAY AROUND. I planned on pumping water into the fishtank from the sump pump and at the same time pumping water from the fishtank into the growbed irrigation lines. Bad idea, it relied on one very poor assumption: That both pumps would move the same amount of water. Not true, even though they were the same model, the small difference in heights and a couple of other factors caused one pump to pump more water than the other which means that, either the sump tank would run dry eventually, even if only until the next cycle kicked in OR the fishtank would overflow. Here's the biggest mistake I made though, If both pumps are turning on at the same time and cutting off at the same time, then the sump tank will overflow because the water drains out of the growbeds even AFTER the pumps have shut off and when the pump turns back on, the water coming into it from the growbeds means the sumptank will not have enough time to "catch up" and will eventually overflow. Ah, so I thought, I will just reduce the flow the water going into the growbeds so as to make sure the water coming from the sumptank always moves more THEN I will put in a drain line so that when it does eventually over flow, it will drain right back into the growbeds. See what I'm doing here? I'm making up for faulty design by adding needless complexity to the system. Even if I had done this, the system would never had been perfectly balanced as the overflow from the fishtank would have probably overflowed the sump tank eventually.

Onto the newest idea. I stumbled across and ordered a float timer. I never even knew these things existed. the way it works is you mount the float to a piece of PVC by clamping it on at the level you want your pump to kick on. You then plug your pump into the outlet provided with the float switch and when the water hits that level it will kick the pump on and drain it back down to that level. This is a much simpler solution as it is reactive to the level of water in the sump tank, not time.

 My plan now is as follows.

Plug up my drain lines in the bottom of the growbeds and pump water from the fishtank into them until I get the water to the desired level. (about one inch below the surface of the gravel)

Make sure there is enough water in the sumptank to cover the pump so it won't suck air while the growbeds drain.

Set the pump float to that level of water.

Open the drains on the growbeds and let them drain fully into the sumptank and plug the pump into the float switch outlet.

Now, because I have taken the amount of water out of the fishtank that it takes to fill the growbeds, I know the water will never overflow the fishtank. Even if it somehow did, I have an overflow tube as well.

Once I have my float set I can drain the water from the growbeds into the sump tank, the pump should kick on very soon and pump until the float drops again below the desired water level in the sumptank.

I will still have the second pump in the fishtank on the timer to start the cycle every 15 minutes but 15 minutes should be enough for the drainage of the growbeds and the pumping of the water back into the fishtank, getting us back to the start of a new cycle.....In theory. 

Basically what is going in is I am adding a pump, which is triggered by the water level in the sumptank, to replace the loop siphons which I couldn't get to work reliably. I think I may eventually rework the drain from the fishtank to the growbeds with the intent of removing the pump from the fishtank but if I can just get this working as it is now I will be satisfied for right now. 

Oh, I almost forgot to explain how the beds are flooding and draining. What I did was replace the loop siphons with a simple piece of PVC with male threading on the end then placed a screw on PVC cap, I then drilled holes in the cap to allow the water to drain but not as fast as it would fill up. I then installed valves on the ends of the four PVC lines running to the grow beds so I could adjust the rate of the water coming in, to get them to flood quicker or slower. By letting the pump run in a few 15 minute cycles I got them to acceptable levels of flooding but I also installed overflow valves just in case. As it stands right now a couple of the beds drain pretty fast because I drilled 6-9 holes in the PVC cap but they still flood during the 15 minute cycle, I could actually lower the drain rate by putting a PVC cap on the drain line with less holes (maybe 4-6) and then reduce the water rate at the valve. This would allow me to add more grow beds as it seems like I would have enough flow even in 15 minutes to flood more beds.

I am supposed to meet a guy this week in Rome Ga to get my catfish. he is over in Alabama but comes over to Rome ever couple of weeks so that saves me having to drive to Alabama to get them. I have a few goldfish in the water now and they seem to be doing ok although I have lost about 12 or so out of the original 36. I am attributing that to the cooler temps at night as the water appears to be chemically ok and I know I have been feeding them.

Aquaponics 4th post - GETTING CLOSE!

Time to bounce some numbers around. I purchased a pump (actually 2 in case one goes bad) that pumps 400 gpH. An esteemed colleague reminded me that I had to consider the height at which I will be pumping to and consider that the height will reduce the amount of water being moved. (Thanks TCLynx) I found a chart on the side of the pump casing that shows how much volume drops off as the height is taken into consideration. It's a little bit of estimation on my part as but I think I'm pretty close. I am pumping the water to an elevation of about 46 inches or almost 4 feet above where the pump sits (on the ground in a sump tank). According to the chart I should be moving around 250-275 gpH, which is almost exactly the amount of water I have in the fish tank now. I believe that since I am not fully stocking fish in the tank to its suggested capacity, I may have a little margin for error in regards to fish safety. One of the reasons you want to move the water it to make sure the water stays clean for the fish. Since I have less than the full capacity of fish I am thinking I may have quite a bit less fish waste to remove with my growbeds. I had fairly limited rooms for growbeds so I think I have higher capacity for more fish than I do space for plants. I can add more fish later if I decide to add a couple more grow beds. As it is I anticipate have plenty of fish waste for the four growbeds and my fish won't be as crowded. So now here are my numbers calculations

Pump - 250 gpH = 4.17 gpm

volume of growbeds with pea gravel = 20 gallon

It has been noted that when adding water to a growbed with peagravel in it, estimate that 40% of the volume of the growbed is how much water will be needed to flood the tank to the gravel line, BUT we don't want to fill it to the gravel line, just about 1-2 inches underneath the gravel line. Since 12 inches of pea gravel gives us about 20 gallons, 10 inches would give us 16.6 gallons. Thats the 20 gallons minus 2/12 (1/6) since we're losing 2 inches because we only want to fill the growbeds to 2 inches below the gravel level. We are estimating the water needed to fill one bed is (40% * 16.6 = 6.64). It should take just over 6 and a half gallons of water to fill each growbed to the desired level.  Given my pump volume of 4.17 gallons per minute, I timed the time it took to fill in from the overflow tube from the fish tank ( overflow should be the same as pump volume). It took about 90 seconds to fill the growbed with water so that would be 4.17 * 1.5 minutes for a total of 6.25 gallons of water to flood it. I could have been off a few seconds with my timing but as you can see the numbers are really close so my estimates are fairly close to correct. My plan is to start out with 4 grow beds. I had wanted to do 6 growbeds but space is very limited in the greenhouse. I may add 2 more growbeds later but they will probably have to be outside. Also I bought 1/4 ton of pea gravel and that amount filled 4 growbeds and I had one 5 gallon bucket left over so I didn't really want to get another truckload right now.

Since our water flow into the growbeds is a constant in this scenario,  if it takes 90 seconds to fill one growbed it should take 360 seconds, or 6 minutes to fill 4 of them. (4 growbeds * 90 seconds) Technically we are dividing the flow by 4 which means it takes 4X longer to fill. Or you could call it increasing your growbed volume by 4 and going at it from that angle, it's all the same.

 As a side note, the most time consuming thing so far has been washing the pea gravel, it took literally hours to wash and then I had to do individual bucket loads to get as much dirt off as I could and EVEN then the water is a little cloudy. I don't know there's any functional disadvantage to having small amount of dirt in the system, possibly it could clog the pump filter I guess but mainly for me it's an aesthetic issue, I want to be able to see my fish. I am hoping the dirt will settle to the bottom of the growbeds eventually but I just simply got tired of washing the rocks. Any water I saved on doing aquaponics has MORE than been off set by the water I used washing the rocks. Even so, the water is not really wasted of course, it simply gets absorbed into the ground and then either eventually evaporates back into the air or finds it's way to water a plant or just slips back into the water table, At least that's what I tell myself. 

 Now we have to figure out how long it will take the beds to drain. With the setup like it is now, it actually fills up faster than it drains but of course that will change when we reduce the flow by 75% by splitting it four ways. When I tested it with one barrel it drained slower than in was being pumped in so it would have overflowed had I left it on. This was not what I expected as I used the same size pipe for the drain as I used for the overflow so I thought it should drain at the same rate. This was not the case, I am attributing the slightly slower drain rate to the present of small rocks at the mouth of the drain pipe inside.  If it takes 6 minutes to fill all the growbeds, since the beds are constantly refilling even when they are draining, we should be cycling the water about 10 times an hour in the growbeds. I will test this as well when I have all four beds up. Realistically I expect it to be less than this as I think the water is going to drain slower than I had anticipated at first. I think as long as it cycles at least 6-8 times and hour it should be fine. I think the plants will have plenty of opportunity to get their nutrients with that many cycles.

 I am considering putting some form of filter, or strainer over it to keep small debris out of it. The is particular pea gravel may not be the best as there are lots of good sized rocks but also a lot of very small rocks. I foresee these may be a problem unless I add something to the drains to keep them from getting clogged. That being said I have heard of people who say sand is an option as well so other that the draining issue I don't think the small size of the rocks will be an issue. As a matter of fact it may be beneficial in that it provides more surface for the bacteria to live on and may be slightly better at anchoring the plants.

At that rate, since the beds are constantly refilling even when they are draining, we should be cycling the water about 10 times an hour. I will test this as well when I have all four beds up.

     I put about 30 guppies in the tank last night just to see if the water was capable of supporting life and they seem to be doing fine, they fed and were active. I lost 2 overnight, one I think because it got sucked into the overflow tube at the top of the fishtank and one that just seems to have passed on from the mortal coil and stays on the bottom of the tank. Curiously enough, I had one fish that got sucked into the overflow tube, into the hose down to the sump tank and survived just fine. I transferred him back to the main tank.

I also added some nitrifying bacteria I found at a Pet Land, they wanted $50 for a liter and I told them no way, manager said "I'll go half price on that." so it would have been about the same price if I ordered it online, maybe even cheaper. It is a product called Nutrafin Cycle and the store manager assured me it only had natural bacteria in it so around next summer when I'm eating the food from this garden if I grow gills or a fin on my back you can all go after the store manager at Pet Land hahah. 

Sorry no pics on this blog but the next one should have plenty.

I am sad that the 2 fish died, even though I knew some would, but it feels so ... rude... to disregard their deaths so easily so I have decided to name them, to give them an identity as a fellow being on the planet and as a way of mourning their passing, so... Goodbye Deadfish 1 and Deadfish 2, you will be missed, not so much by me but by Live fishes 1-28.

Aquaponics 3rd post

Ok, third installment, now we're starting to put some stuff together. The below picture is of the tote after I cut off the metal top of the frame and the top of the plastic container. I tried using a jigsaw on the metal bars but broke 2 blades. I cut one side off by hand using a hacksaw but that was pretty time consuming so I gave the jigsaw another try. Turns out I wasn't placing the blade correctly and it was jamming it into the metal and breaking it. Oh, well live and learn. After I picked up that little piece of info the sawing went much smoother. 

 

Below is the tote filled with water and inside my greenhouse, the tote is big, takes up about 40 inches and the greenhouse is only 6 feet wide so you have to squeeze past it but it's not that bad. It will be worth it to have it under cover. It's a more controlled environment, It will be warmer earlier and more protected from rain which could add unwanted water to the system. Also cuts down on contaminants like cut grass and debris. 

After doing a little research I was a bit worried about what the local water department puts in the city water to purify it. Apparently chlorine gas will dissipate if you simply leave the water outside a few days but some places uses something called chloramine that is not so easy to remove. But after a couple of phone calls to the Calhoun water department I was able to find out that it is in fact chlorine gas. Guy on the phone even said I could come by the water department and they would give me some little test kits to see if the chlorine was gone.

Well, after much worrying about it, I think I found what I needed at Home Depot to seal the places where I will be cutting holes and adding pipes. I was worried about it leaking. Most of the time when you are using PVC you're worried about the water getting OUT of the pipe from inside. I was worried about it seeping outside the PVC fitting. But a little searching and I found what I needed, it's a 3/4 inch "L" fitting with a plastic nut on the inside with an O ring. I think it was $2.85. The top end pictured below has a 7/8 inch (I think) barb on it to insert flexible tubing over. This is what I needed as I am using a loop siphon to drain the beds. There is also a little black foam rubber ring on it too where the flexible tubing will seat onto the barb.

Below you can see the inside of the "L" adapter, the little round nut there flattens the O ring when tightened and seals it off. Seems to work pretty well, I didn't notice a leak. Even if it does leak a drop or two every couple of hours, I am not all that concerned but I didn't notice a constant leak at all. If you use something like this be careful not to strip those threads, I was using a pair of channel lock pliers to tighten up the nut and it is possible to twist too hard and strip the threads.

Below shows how I have the flexible tubing suspended to just about the right height through use of a copper conduit hanger, the hanger is normally used to suspend copper or PVC when running a water line but I took a pair of pliers and twisted the ends so that they would hang off the edge of the barrel. Not sure if that's the solution I will use eventually but it works fine for "beta testing" or proof of concept. Hardest single part of just about everything so far was getting the flexible tubing over the barb, even though it was the right size it still took a little elbow grease to get it in. I think in the future warming the hose or at least the end might help.

Just to test the siphon I made the loop and then put the other end of the flexible tubing into another half barrel. I couldn't get the siphon to kick in at first but I discovered it was because I had so much slack in the hose and there must have been air pockets in the tubing that weren't being pushed out as the water level rose in the barrel. My hypothesis is that the force of the water pushing into the tubing wasn't great enough to force the air out of the other air pockets further down the line. I'm not sure if that is the exact reason or not but when I cut the tubing to a shorter length the siphon kicked in like a charm.

Incidentally, Home Depot had these little green handled clamps show below for .99 cents and I bought a few, one of the best dang purchases so far, already got my money's worth out of them.

 I wanted to test the loop siphon a couple more times so I went ahead and sat the submersible pump inside the second barrel half so I could move the water back into the first barrel, which will eventually be a grow bed. Interestingly, the water drained out at only a very very slightly quicker rate than the pump pumped it back in. The pump I have is rated at 400 gallons per hour and an 8 foot head. Now, if we were just filling this one grow bed that might not work as it would take a long time for the water to drain because it would be filling back up about as fast as it was being drained.  . Because my fishtank is so tall, I have decided to use what they call the CHOP method which stands for Constant Height, One Pump. This means the level of water in the fish tank stays relatively constant (Constant Height) and you use One Pump in the system.  Because we use gravity as a big part of the system, we need our water to flow DOWN into the growbeds, since the fishtank is higher. What will happen is there will be an overflow tube which is constantly overflowing into the growbeds from the fishtank. The pump from the sumptank will be constantly pushing water into the fishtank, which in turn will constantly flow into the growbeds. The growbeds will fill until the water reaches the level of the highest point of the flexible tubing, which is looped outside the growbed, at this point the water will force out the last little bit of air in the loop siphon and the siphon effect will start draining the tank into a third tank (Sump tank) sitting below the growbeds. When the water level reaches the level of the "L" adapter at the bottom of the inside of the tank, air will enter the pipe which will "break" the siphon and it will stop draining and start filling up again. The sump tank is where the pump sits, constantly pumping clean water back into the fish tank. 

A great explanation of how loop siphons work is available here.

http://aquaponicswiki.com/index.php?title=Siphons

Next up is rigging up a table for the growbeds, getting the pea gravel and preparing it and putting some "test" fish into the tank. I'm going to get some cheap goldfish to make sure the water is ok. No, I am not intentionally killing the little guys, I will test the water first with a water quality test kit and expect them to do just fine. I just want to test it before I spend the money on my catfish.

Aquaponics second posting

Got the greenhouse up with some assistance from my cousins

.....ok lots of assistance

...... ok they did most of the work and I stood by and tried not to look useless. It's a nice little greenhouse, Dale and Aimee both commented on it. I think I paid about $150 for it.

 The frame is made out of tubular galvanized steel, Dale seems to think it will be sturdy. It could be made out of aluminum foil for all I know. That's why it's good to have family who understand the "real world application" of things. Kiersten and Dale attaching the supporting braces. Luckily my backyard is fairly flat, so we didnt have to do any digging. There is a couple of low spots but a few well placed homemade shims should do just fine.

The measurements are 6' by 12' I think and the top is 6 feet, just about right so I don't have to stoop over to get inside. My one concern is it being high enough for tomato plants, that's the main thing I want to grow and if things go well, I can foresee tomato plants growing straight up to the ceiling fairly quickly. Oh well, let's see if I can get the system working first, over growth of plants is a good problem to have.

Aimee silently volunteered to serve as foreman, she has a good eye for detail and caught a few mistakes we were making early on.  

Aimee, as foreman, is always tactful, seeing as how her husband is packing. 

 The fabric is clear with interwoven green strands, seems very durable. It is curved and slips right over the top of the frame. Some of the cool things about it are double zippers on either side as you can, as well as little holder straps to roll up the doors if you want more fresh air. Also there are little "windows" on the side you can roll up as well, also with holder straps.

  Here's the finished product. Looks neat, not an eyesore at all. Inside we used tent stakes to anchor it but I am, not fully convinced a strong storm wouldn't loosen it enough to fly off, it's very light weight. When I get the 300 gallon fish tank inside I will strap it to the frame and that should prevent it from going anywhere.

My tote just got delivered. It's a 330 gallon tote that has had only food grade product in it. The owner said it had had some type of citrus based product but was non toxic. These things are $475 new, but companies are only allowed to use them once then they have to be discarded. I paid $75 for this one plus $10 delivery, very fair deal I thought. Also on a side note, the guy I bought it from was somewhat of an expert on fish and aquaculture, he had some good input on fish and fish health. He actually raises Koi, I may get a few from him as he said they could live alongside the catfish, I plan on harvesting the catfish at some point so it might be a good idea to have fish that stay in the system to keep producing waste after I harvest the catfish and while a new batch grows to size. From what I read, stability and not upsetting things once they get set is a good idea.

 Below, not sure if you can see, but there are gallon and liter markings on the side of the tank, awesome, as I will know exactly how much water is in there, might be kinda hard to estimate with having some type of measuring device. 

Also, not that I will use it, but this tote has a pressure release cap on it, may not use it for this setup but in the future that could be helpful if I decide to setup one of these tanks as a solar heat collector.

Lastly on the tote, it has a very sturdy looking ball valve on the bottom. The tote looks extremely rugged and I am well pleased with the purchase. Thanks Mickey! (tote-guy)

I have purchased 2 pumps on ebay, and yes I went with a cheap model to get started but I did buy 2 just in case one fails. It is a sump pump that pushes 400 GPH with an 8 foot head. Should be plenty of volume as you are supposed to move at least the volume of the fish tank once per hour. I toyed with the idea of a more powerful sump pump but I wasn't sure how I was going to regulate the flow and didn't know if I could use a timer or a float switch. It seems to me that just leaving one on constantly may be the simplest thing, at least to get started.

Next up will be getting the tote cut across the top, hope I can find my wireless saw. Also I need to go ahead and find where I'm going to get my pea gravel from. I think a half ton will be enough to get me started and my Ford Ranger should handle that. I am expecting to pay about $50 a ton for the pea gravel. So for those  keeping count, my estimated cost so far:

Greenhouse                                             $150

Tote                                                      $  75

Pumps (2 @ $30 each)                               $60

Pea gravel (est @$55 /ton)                        $55

Barrels (@$12 each)                                  $36

Sump tank                                               $60

_____________________________________________

Total to date                                          $430

Yeah I know, with the money I spent I could probably buy organic vegetables for 2 years but hey, it's a hobby and I'm learning all about ecology and stuff. Besides, there is a very satisfying feeling from eating something you raised yourself.

Aquaponics

Aquaponic install - First attempt

I have been gardening for a couple years now, mostly container gardening, where you build containers, add soil and plant something every square foot. I usually built the framework of a box and sat it on the ground. I would put down some weed guard underneath before I added the dirt to keep weeds out. It works pretty well, but because I built them on the ground, you still had to bend over to work on them, not a big deal but still not optimal for a lazy person such as myself. In any event, in my reading of gardening ideas, I came across the idea of aquaponics. Basically it works out like this. You have a large fish tank, the fish excrete waste and ammonia into the water. Now if left alone this water will eventually become toxic to the fish, the waste would kill them, so we have to have some way to clean the water, in comes the plants. See, when you set up a plant bed in aquaponics you use growing media, not dirt. You can use pea gravel or lava rocks or any of a number of media. In any event these beds will develop bacteria, this is good for a couple of reasons, the bacteria will work on the fish waste and turn it into fertilizer for the plants to use as food and by removing the toxic fish waste, it purifies the water so it can go back into the fish tank. 


That's the basic concept, in reality it mimics an ecosystem, all things in  balance, just like nature. It's interesting to me that as we become more advanced we find ourselves looking more and more towards to nature for a template of how to do things. The fish waste acts as fertilizer for the plants and the plants in turn purify the water, via the bacteria that transfers the waste into nitrates. This system uses 1/10th the amount of water of standard gardening as all of the water is kept in a closed loop for the most part. You will have some lost to evaporation but on the whole it is far superior in terms of water usage as compared to standard farming. As a side note, the latest revolution in solar energy actually mimics the actions of leaves on a tree. One day we'll be able to cover windows and glass doors with a translucent photoelectrochemical film and generate electricity as well as still see through the film.


So back to aquaponics, I am going to try to document my successes (failures as I see fit, haha) so you can see how easy it is.... or how much fun it is to laugh at someone who has no clue what they're doing. I'm still in the design phases but here's what I got so far:


Fish tank- Found one of those 330 gallon totes on craigslist for $75.00. Here's a pic of what they look like.

I am going to cut the very top off and I should have about 300 gallons of water space. I had planned on trying a smaller tank at first but someone off an aquaponics forum advised making the fish tank as big as possible because a bigger tank makes the system more tolerant of mistakes. Apparently the smaller the system the more a small mistake can have catastrophic results. On a side note here, it is important you know what was IN these totes. You want to make sure it was something safe

Grow Beds- I found a guy down the road who has food grade plastic barrels for $12 each, that's a really good deal as most of the other places I found them were a) out of town and b) $20. Plus the guy has hundreds more. I will be cutting these in half and filling them with pea gravel as my grow media.

I may cut them in half horizontally, I have been told that works better if I use the type of drainage method I want to use.

Fish choice- I think I'm going to go with catfish. Tilapia are the standard choice since they are very tolerant supposedly of mistakes in water quality. But I know I like to eat catfish and I always like to be a little different anyway. Heck, I might even through in a few freshwater shrimp if I can find some the catfish don't eat.