I would like to seek for your advise on this topic.
About a year ago I set up an aquaponic farm; I have two independent systems (let's call them system #1 and system #2) under the same greenhouse; each system has 2 IBCs as fishtanks, 15 square meters for growbeds, and 5 square meters for floating raft.
Each has two IBCs as sump tanks.
I started with Tilapias - big mistake because of temp- during winter I spent thousands trying to keep water at a decent temp.
On jan, I gave them all away, cost was crazy.
Then I got trouts (240 fingerlings, 60 for each IBC).
They were doing great at first, but one day, around 100 of them died suddenly, all from system #1: My immediate thought? oxygen -- so besides the 4 air pumps I already had for both systems, I got 4 additional 60LPM pumps and 8" airstones, and put one for each fishtank.
On march, 10 more died out of the sudden, no reason -- system #1 again.
On april, 2 or 3 more died, so I got tired and started checking up system #1, I took all the fish out from that system and put them in a separate, 300 liter tank with fresh water; I do water changes every 5 days -- water is sometimes soo dirty I cannot see the trouts -- but nothing happens to them -- happy and eating.
Yesterday, I decided to take around 100 liters of water from system #1, and mix them with other 200 liters of fresh water, so the remaining fish could start to acclimate to their original system --- today, 2 of them dead. pH: 6.5 on system #2, 6 on system #1
Nitrites: very low on both systems
Nitrates: around 20 - 50 on both systems
Ammonia: 0.6 on both systems
Water temp: oscilating between 15 - 17 C daily.
EC: 0.351 on system #1, 0.353 on system #2 ppm: around 200 each system.
I did a complete change of water for system #1at the end of march.
Plants in system #2 are beautiful, but in system #1 are very small, they look sad. I just donÂ´t understand why the fish suddenly die, during night. IÂ´ve cracked my head for months now, and I cannot seem to find the answer; also plants are not growing as they should.
Is it possible that some plants affect the water or the fish in some way? I ask you this because in one of the grow beds I have some very nice little plants, like water lilies, except they grow on soil; Also I keep a very small plant of levomenthol - I keep them because my mother likes them and uses them - but I am starting to think maybe some plants are affecting the chemistry in some way.
Is there anything you can think of?
Thanks in advance.