Backyard Aquaponics
A place to discuss aquaponics

My system is made of 3-275gal IBC's. The fish tanks are about 175gal. The GB's sit above them and are filled with lava rock. The middle tank acts as a sump, so has a fluctuating height, the other 2 tanks have constant height. The GB's are set up as flood/drain, using bell siphons. I cycled my system in august of this year. I did it fishlessly, using ammonia and a filter from my established koi pond. I was quite generous with the ammonia. It cycled fairly quickly, but the nitrates were very high. I had started some lettuce and broccoli during this time. After cycling I added 20 LM bass and 20 Cats. All were fingerlings. Since that time I have had some fluctuations in pH, sometimes dramatically, due to my over-zealousness . It has now stabilized around 6.8-7.0. Ammonia=0, Nitrites=0, Nitrates off the chart. I use the standard test kit and the result is RED. I have tried doing the test at half strength, but it also came out red. The color scale only goes up to 160, but even that is not red on the comparison card. I did a considerable water change with no noticeable change in the nitrates. This whole system is in a 10' x 20' solar greenhouse with Solexx panels. The temperatures range from 65 -110F.

So that's the set up. Now for the plants. The new growth looks fairly green and healthy, but as the leaves age by a few days they start looking progressively less healthy. They start yellowing, curling and getting crispy. Some of the leaves, such as the sweet potato vines developed minuscule black dots. These were not bugs and did not rub off. These became more noticeable until the leaf died. The broccoli has actually done the best, but again, the older leaves crisp around the edges and finally fall off. The transplanted green peppers have lost all their leaves, attempted to grow new ones and lost those too. About once a week I add 1 Tbsp of Maxicrop or SeaCom. On occasion I throw in some Fe, K.

I have spent quite a bit of money and a lot of time on this project. At this point I am finding it extremely frustrating.

Any help would be greatly appreciated.

Hello IRockLobster
I am new to AP so dont want to give you wrong advice
Can you maybe post some pics of the plant/leaves.
I know the wise/old AP guys on the forum like to see pictures and then analyse from there
Hope you get sorted

Post some photos as BamBam suggested, and maybe put some more plants in if you can. The fact the new growth is healthy is a good sign, it might (hopefully) is just a simple case of not enough plants for the amount of nitrates.

As the other two posters have said,Pics.
Very high Nitrate levels will hinder nutrient uptake,especially Potassium and Magnessium,i know you have said you have water changed to reduce these levels.Your feeding although you don’t say what it is,keep them frugal rations until your nitrates at least get back on to the chart and smaller regular water changes are better than one big one to help reduce your nitrates,when you say you were generous with the ammonia you weren’t kidding were you.....
Dont despair,all will come good,one tip don’t be to eager to and i quote,On occasion I throw in some Fe, K. when you put something in the system you need to have a reason to put it in,because as you found with the Ammonia,once its in there theres not much room for turning back.

Thanks for the replies. I was thinking that maybe the problem is K deficiency since the root growth is scant and the older leaves are yellowing and crispy. I added 1 tbs of K 2 days ago and again today. I added 1 T SeaCom 3 days ago and again today. I will get some pics tomorrow.

Thanks again

It looks like Potassium, Magnessium and maybe phosphates,if your nitrates are really high this could be your problem,try to bring them down,to help maybe foliar spray,if this was me i would spray a mix of MKP with maybe two tablespoons of epsom salts per gallon,this will surely help until such time as you lower your nitrates.

I appreciate the advice. I did a 25% water change, but the nitrate test was still red. I made a foliar spray of 1 qt of water with 1.5 tsp epsom salts, 1 tsp K, 1/2 tsp SeaCom. We'll see what happens.

Hello
Hope the plants are doing better

Well, I have been doing frequent water changes and the nitrates are finally starting to come down. Don't get me wrong, they're still too high, but now the half-strength nitrate test only shows dark orange instead of bright red. I also just bought some water hyacinth plants to help reduce the nitrates. I have many little sprouts coming up. All seem healthy so far, but the long term will be the test. Here's hopin'.

How do you like your Solexx panels? I am outside Greenville SC and we are building a passing solar greenhouse. You’re not that far from me how are the temp’s in your greenhouse.
How many barrels did you use for heat storage? I think we are going to use 20.
We are looking at building a 12x24' or a 14' x 24'
Where did you get your Solexx panels from?

I love the Solexx. I originally ordered the 3mm type, but it was out of stock, so I got the 5mm. It was very easy to install. Took 3 people, but it went quickly. My GH is 10X20. I bought 20 barrels, but they did not all fit. I think I have 16 or 17 in there. I got the operation up and running in august of last year. Since the ventilation is good, the air temp didn't get much over 85-90 during the heat of the day. The water was about 75. This winter I am heating with a propane heater. I have sealed the GH up and allow the daytime temps to go up to 100, so as to heat the water in the tanks and ballasts. I don't let the nighttime temps go below 60, therefore the water temp stays at 60 as well. I use a 100lbs propane cylinder. In January it lasted 2-3 wks. A larger tank would be more economical, but can't afford it right now. I got the Solexx from Greenhouse Superstore.