high nitrate level and elevated ammonia

[john taylor]

have had my system running for approx 7 months , have 150 gal tank pumping into 3 -25 gallon grow beds ...have not had much success growing plants of any kind ...using pea gravel and bell siphons ...the system works great mechanically....have 34 talapia  ranging in size from 3 inches to 10 inches long ...feed  med pellet cichlid food 2 times daily  what they can eat in five minutes have approx 25 plants  ranging from  a large peace plant to 15 or so marigold  and other various garden plants ...am alternating lighting  , 2 lowers in afternoon ,2 uppers in evening and turn off at morning ...full spectrum lighting.... my ph is perfect as is the nitrite level  its the ammonia 50ppm  and nitrates 80ppm  that stay elevated   and all plants are extremely leggy... grow up and not out . do approx 40 gallon water change every sunday and the ammonia changes very little and the nitrates not at all...while i have lost no fish so far  i feel that without the benefit of the edible food  i'm just spinnin my wheels . i would really like to see this project come thru for my family . any suggestions will be greatly appreciated

[Chip Pilkington]

Hi John,
Water changes are another no no. Once again, AP is different tha keeping fish in an aquarium. Adding top up water is about the only thing required, outside of a sick fish scenario. Water changes actual disrupt the cycle/balance in your system. Depending on the size of your system and quality of tap water, you may not need to treat. I use rain water and/or off gas tap water in a barrel for top ups. I go through about 200L a week, so there is new water coming in, but I never drain off old water. Once again, a sick fish scenario is different.

[john taylor]

ok so i can use the water from my 12 rain barrels as just a top off  without having to treat ..what about the settling of fish poo on tank bottom  does that need to be removed ?

Chip Pilkington said:

Hi John,
Water changes are another no no. Once again, AP is different tha keeping fish in an aquarium. Adding top up water is about the only thing required, outside of a sick fish scenario. Water changes actual disrupt the cycle/balance in your system. Depending on the size of your system and quality of tap water, you may not need to treat. I use rain water and/or off gas tap water in a barrel for top ups. I go through about 200L a week, so there is new water coming in, but I never drain off old water. Once again, a sick fish scenario is different.

[TCLynx]

Top ups good.

If fish poo or uneaten feed is settling in the tank and not being moved to the grow beds then yes you need to remove it.  You might try adjusting the flow and aeration to the tank to see if you can get the solids to be sucked out of the tank without you having to mess with it yourself.

[Chip Pilkington]

I struggle with that as well - I have repositioned my pump (I don't use a sump, so I pump directly from the FT), but still have some solids. Someone on another site commented that they just take a sweep with a net on occasion (especially if you have big waste producing Tilapia). I've been doing that recently and it works pretty well. I'm always poking my head in the tank while feeding (my fish are very friendly), looking for anything out of the ordinary so it's not a big deal. The stuff that goes through the pump gets chopped up and pulled out in a swirl filter before the water hits the GB's. It's not a typical setup, but my water quality is excellent - tests right where it should.

Anyway, sounds like you're on track.