Backyard Aquaponics
A place to discuss aquaponics

ah I've been remiss in my updates.

We harvested the catfish from this system as we decided the stock tank was not really deep enough for catfish grow out the way we like to do it.

This system has had 60 blue gill for a while now and they have been growing well. The nutrients have been way low for what I'm used to. Been between 5-8 ppm for weeks even as I've been upping the feed and it is high protein feed too.

Well I haven't been running air in this system for the past couple months to see how well it got along without. There is constant water flow the way I have the drains from the sequenced beds going and this was working well enough with small fish but now that the fish are getting bigger and the temperatures are staying so high, well I noticed the fish are a bit off their feed the last few days. Time to put the aeration back in.

Hey TC,
I assume those tanks are 2' deep? What depth would you recommend for cats?

Mikey

yea those 300 gallon rubbermaid tanks are only 2 feet deep so the actual water depth is going to be even less.

I'm thinking the new tank I have for my Tower system is a far better depth for minimum tank size for big Catfish. The tank is 34 inches in total height and I'm running the water level in the tank at 27 inches and I think that will be an appropriate size tank. Now you can go deeper. My old in ground tank had around 3 feet of water in the deep part when the water level was low and my current big system Big tank runs a water depth just over 3 feet deep.

Ok back from my latest trip.
Have had 90 bluegill in the 300 gallon system and since I added air they have been eating up all their dinner and the tank is looking clean so I can up the feed again I think. Water test all comming back good and the nitrates still way low for what I'm used to. I'm even seeing signs of nitrogen deficiency since I have lots of greedy plants in the system. Deep grow beds do not seem to be setting this system back in relation to the plants being able to use up nutrients of a heavy fish load.
And this system seems pretty hardy as far as the bio-filter goes. When there were no fish in it I was able to dose up to 4 ppm of ammonia and within 24 hours both ammonia and nitrite were back to 0 and even with sudden fluctuations in fish load and feed levels the ammonia and nitrite have stayed 0 in this system very nicely this year.

Some pictures to prove what I say.

Actually even with 90 bluegill in this system it looks as though I'm only barely getting enough nutrients to these greedy plants.

Having enough aeration is the key to sooo many things...

Yep - there's a documented direct link between DO levels and productivity (in conventional aquaculture).

Yep, necessary for fish respiration/metabolism, conversion of feed to protein... and nitrification...

And plenty of air keeps the water turned over to

Looks so nice and productive over there at the moment, here it's just freezing cold....

Actually that system was nice and productive during the cold too. Broccoli likes ice here. I just have to take the shade cloth down for the cooler months. It has actually been a bit cooler here the past week like with the highs only around 30-32 C and a fair bit of rain.

I'd been testing to see how much I could push this system without the supplemental air. Was going quite well but as it got hot I could tell when I was getting close to the limits. Basically it seemed to be about when the night time water temperature quit dropping below about 80 F or 27 C.

Air stone in and things got better, I was able to bring the feed level up. But still the plants are greedy and the nitrate test just shows the lowest amount of nitrate and some of the plants are showing a little bit of nitrate mobility steeling it from the lower/older leaves to keep on growing. This is the first time I've tried corn in AP. It's popcorn not sweet corn.

newbie, but pond nut. At night the plants will begin to use up the O2 and that is why the o2 levels in the water drop and the added air is needed. Warmer water also holds less o2 than cooler water.

If yah all know that already please ignore this post!

MW

This is why I added the air back into this system. The plant beds on this system are flood and drain so the issue isn't much to do with the plants taking up the O2 (no algae in the water to speak of either) but everything to do with the warm summer temperatures on this 300 gallon fish tank system.

Now I did lately set up a little pond for some pond plants and I tossed a few fish in there to take care of mosquitoes and those poor fish the first evening as the sun went down were immediately gasping at the surface and caused me to add much more pumping to that little pond just to keep the fish from dieing over night as the pond plants used up all the oxygen.

Quite the ap jungle you got going there Tcl. Looking really great.

Just an FYI the moringa in the background is in the ground not the AP