Backyard Aquaponics
A place to discuss aquaponics

Greetings everyone!

I live in the hot humid Alabama coast and I've decided to build an aquaponic system.

So far, I've got a single use IBC (formerly had farm fertilizer in it - water soluble and no pesticides, so it all should come out with a good cleaning). And a blue 55g drum (formerly held H2O2, which also is water soluble and should come out with a good wash). These cost me $115 (including delivery - I thought that was a deal).

The plan is to use the top 12" of the IBC as a media grow bed, and the rest of the IBC as a fish tank. The 55g drum will be a sump. In other words, what I have gathered may be called a basic IBC CHIFT PIST system.

I've got a 530GPH pump that claims to have 430GPH at 4'lift, which is more than I anticipate needing.


The basic design is attached as a picture. Hopefully it uploads.

I have a lot of experience with aquaria and gardening, but my aquaponic experience is equal to that of a newborn monkey, so I have some questions.

1. Is the pump sufficient?
2. We get TONS of rain here, so collecting rainwater is easy. But at some point I'll need to use the hose. Should I use a chemical dechlorinator or some sort of charcoal filter?
3. Can I grow tilapia here without spending tons of money on heating? I have run I'm planning on building a wood frame around it with a lid to satisfy the wife's aesthetics, so that should insulate the water fairly well. We generally don't get a hard freeze but 2 or 3 times a year. The rest of our 2-month winter means days in the 50s-60s and nights in the 40s-50s.
4. Will the entire 55g drum be needed for a sump? If not, I'd like to use the bottom as a sump and the top maybe with a small raft.
Like this here:
5. Can I grow duckweed in the sump? I've read that fish like to eat it as a supplement.
6. Would the fish tank be sufficient to add a couple of NFT pipes above the GB?

Thanks a ton for any advice.

1. The normal guideline is that the pump needs to be able to move the volume of the fish tank once per hour at whatever head height you are pumping to. Head height is the distance from the top of the water the pump is in to the highest height it is pumping to. Most pumps will list this information in the manual. You should also consider the efficiency of the pump since this can save enough electricity money that it makes sense to buy a more expensive pump if you can afford the up front cost.

2. If it's just chlorine you could also just let the water sit for a day before use. If it's chloramine then I'd use vitamin c. If you're only adding less than 20% of the system volume you can probably go ahead without treating, others have had success with this.

3. I don't think you'll have to heat much but I'm not certain. Tilapia should be kept above 55 F although with Blue Tilapia you can go lower (they probably aren't legal for you or most others though).

4. You probably could skip the sump altogether if you wanted to. Most starter IBC systems are just the tank and grow bed above. Maybe use the small barrel for a quarantine system - kind of looks like the photo setup has it that way already with two systems one small one and one IBC setup.

5. Yes but probably not much of it.

6. Yes but you might need a bigger pump for the extra head height.

Scotty,

Thanks a ton. You've answered all my initial questions. The reason I want to use a sump is that I want to have a constant water height without having a timer on the pump.

But I have 2 more.

1. Can I put a small plexiglass window on the IBC so my kids can look in and see the fish?
2. Are there kitchen scraps that fish can safely eat?
3. For temperature stability and fish health, I'd like to have as much water as possible while still having enough grow bed depth. I was planning on making a 10" grow bed. Is that sufficient?

Use Constant Flood, problem solved. If the pump is always on and you're setup to pump using Constant Flood the only fluctuation you'll have is from evaporation. When you're first starting the Constant Flood system fill the grow bed with water so the fish tank won't have to make up that volume. Once it's going it's always on and that's what keeps the water aerated. If the power goes out the water that's in the fish tank stays there and the water in the grow bed stays in the grow bed.

1. I've never done it but it is something you can do. There are at least a couple of examples where people did this if you look through the IBC of Aquaponics (link in the top right corner of this page)(might look for the BYAP threads for those people to see if they have instructions). Web4Deb (Rob) (aka Bigelow Brook Farm) did this on a tank - here's the link to his video which explains the process really well - https://www.youtube.com/watch?v=kGj-qqxSUMc. What I'm not certain about is if adhesion to the plastic used in some IBC containers is a problem.

2. I'll let the tilapia growers answer this.

3. Yes it is deep enough but you lose part of your biofiltration when you reduce the amount of media. I would make the grow bed the standard depth. I don't think increasing the fish tank depth by 2 inches is going to have much affect on the temperature in the IBC fish tank.

Cool. I'll get back to the drawing board and consider the best plan. I'm going to be back on here once construction starts for sure. Thanks, Scotty.

Subscribed! I live down the road from you a ways.

Marty

I just saw an add on craigslist with a guy from south Alabama that is trying to thin the tilapia population in the pond on his property. I would contact him and ask some questions... or for a source for fingerlings.

I went fishing in a pond yesterday that is only about 2 miles from the house. It was FILLED with different types of Tilapia. This is a pic of one of the bigger ones. It was caught by a co-workers little boy. The other side of the pond had swarms of babies in there. So they are able to stay alive in this region in large temp stable ponds. I suspect that they would survive a large aquaponics system in a greenhouse without heating possibly. It would have to be well designed for those occasional below freezing Winter days.

Wow. Is that a white nile tilapia? They have worse cold tolerance than blues, and I figured blues would be the only ones grown around here. That's great news!

If I can ask for a bit of advice: I'm still having trouble balancing the siphon and the pump speeds. I seem to be stuck in one of two situations: either my pump is too weak when the GB is full to activate the siphon because rise rate is too low. I suspect this is caused by the increased head between the GB and the sump, because that is the point where the sump water level is lowest.

But on the flip side, if I increase the pump by lowering the head or putting a solids filter on it (i can raise and lower the hose that feeds the GB), then the siphon activates easily, but when the water in the GB reaches the level where the siphon is about to stop, the pump is too strong: rise rate overcomes the flow rate of the siphon. Because at that point, the water level in the sump is at its hightest (lowering the head), and since the water level in the GB is at its lowest, the siphon flow rate is weakest.

My two proposed solutions are this:

1. Cleanly cut off my intake pipe at the bottom of the GB. It is currently a 1" pvc that runs along one side of the GB. It is drilled with holes and horizontal slots. I think that maybe it's actually decreasing the outflow rate by creating resistance. I think I'd be better off just using a solid filter on the pump instead. Does anyone thing a flared intake would help?

2. Raise the GB a couple inches higher so that my siphon efflux point is lower. This would increase the gravitational pull of the water through the siphon and thereby create a higher flow rate. This would, however, be a huge pain in the ass because even without water in the GB, it's still super heavy.

Any other ideas?

I am going to be honest. These were the first tilapia (alive) that I ever played my hands on. No expert but that is what they looked like. The whites were the biggest. The pond was large... about an acre in size... with lots of shallows on the outer edges. Big enough to take time to get cold. I wish I had been able to bump into the owner to ask how long they had been able to go without restocking.

Reading comprehension is not my strong suite. I will see if I can get a better picture of what is going on to see if I can help. This is my second system and my siphons almost look identical to my first system... but have been extremely easy to tune compared to my first system. I basically tuned them the first day and have not had to touch them since.(only about 2 months). I can see plant roots starting to work their way past the outer 4" PVC pipe/rock screen. So I will have to twist them every now and again as the system matures to cut off roots.

Lets see..


After reading this section I took a look(first couple posts) at the way your system is set up... and did some thinking.
1. What is your current pump flow rate. What is the head height to flow rate scale? I got a pump that has great head height capabilities even though I knew I would not need it. For me means the water will have some force behind it to push solids through that are trying to get stuck.

2. I see that you have a separate barrel on the side to place the pump in the sump instead of in the fish tank... to protect those valuable fish. I am a fan of the Chop system for that... but the Chop system also keeps the pump clean by dumping the fish waste directly into the gravel and filtering the water before it returns to the sump... keeping the pump cleaner as well. Your design does the most important part. However, it is going to have a much larger variation in water height as the gravel bed fills/drains which will have more of an effect on water flow than the minimal water height differentiation that would occur with that large water tank. My new system is not a CHOP system. It is pretty much the same as yours but without the sump. I have the pump in the tank and beds above. So the fish are not protected like you obviously want.

This is what I did. I added a second emergency Stan pipe that sticks out above the gravel layer but below the top of the grow bed. So if there is a clog then there will be no fish loss. Fish Protected. Will almost certainly happen at some point. I would suggest dumping the sump and just modify your pump like I did to minimize work/increase reliability. I took off the small filter screen(don't know if yours can do that and still function) and built a large screen/basket around the pump. When I did this on my first system it went from needing cleaning every 2 days or so to needing cleaning every.... maybe 6 months or more if I remember correctly. Used larger pipes this time that allow no light through and increase flow. Used a 1" ball valve to set the flow for each bed. My pump moves way more water than what my two 1" bells need. So if the mostly closed hole in the ball valve gets poop stuck... it gets pushed through. As soon as I saw poop/feed building up in the gravel to the point it had to flow across rocks before falling down into the bed... I got worms. Red wigglers from Walmart. They had it cleaned within a day and... no more maintenance. More high quality food for the plants. Often most problems can be fixed my making things more simple.

3. My siphons bend just below where they exit the bottom of the bed. The stan tube is about 8~9" (to the top after being installed)and 1" in size. My bell is 2" pipe and stands about 10~11" tall at the cap. The 4" OD pipe has most of it's slots cut at the bottom. Learned that is important the hard way. Makes the bell syphon break better buy draining hard and fast until there is nothing left but the inflow rate. The bottom of the Bell is left flat with it's slots cut starting about .5" up from the bottom. If they are not level they will throw things off. Most importantly the Stan is completely vertical. The 50gal drums in my first system gave me hell. Took me months to realize the stans were not completely vertical. I could not get them tuned. They required an exact water flow. My new ones of the same measurements have a drastically Wider spectrum to where they work. I set them to where it is hard to break the syphon at the end due to water flow. More cycles per hour just add to filtration. If the system starts to clog I will know it a long time before the syphon stops working. They take about 5~10 seconds to start the syphon.

I have more hints and suggestions. I am out of time. I hope you figure it out!


Marty

Thanks, Marty. I have an external U-siphon. I'm going to try your wrap-around filter idea. I actually have some strong wire mesh left over from destroying my snake-attracting chicken coop. I can make it into a cylinder and line that with filter.

Your welcome. I hope it works out. Let us know if there is any way we can help.

I used two pond planter baskets I got from HD. Came in a 5 pack for cheap. Zipped tied them together and cut a hole just big enough for the pump wire and hose to fit through. The holes are small. I didn't add any filter but bet it would not hurt.

Oooh. Just thought of another idea! You could lay the barrel on its side if possible. That would minimize the level fluctuation but would increase the head height unless you were to raise the barrel up off of the ground.


Marty

Don't bother with siphon is the easy route... Doing a simple ibc system I would just put a stand pipe in at the height you want the water in the gb and not mess with siphon, run constant flood like Scotty said. That way fish tank water level stays the same. That's how my first test system ran for several months before I built my permanent beds, but even my permanent beds I'm still running constant flood.