I am looking for advice in how to reduce the nitrates in my tank which are currently at 80ppm. A few weeks ago they were well over 100ppm and I did a 30% water change. Here are the specifics of my setup:
450 gal hex tank on main floor of my house
150 gal sump in the basement of my house (appr. 50 ft of dual PVC pipe between tank and sump)
Dual ATS system (dump style) above the sump in the basement
Apr. 100 fish
-- Foxface Rabbit, Magnifcent Rabbit, Scribbled Rabbit, 4 Hepatus Tang, 4 yellow tang, 2 Leopard wrasse, solorensis wrasse
-- Colony of dispar anthias
-- Colony of threadfin cardinals
-- 2 watchmen gobies + shrimp
-- pipefish
-- colony of blue damselfish
-- 4 clownfish + 4 red bubble tip anemones
Mostly soft corals (have not been successful with hard corals)
2 large clams
Tank is full of live rock with a 5" sand bottom.
I am feeding twice a day, each feeding consists of 2 rotations from autofeeder containing 80% flake (New Life Spectrum Optimum), 20% pellet (Sustainable Aquatics Hatchery Diet) food. I also feed frozen food appr every other day (Rod's). And a couple times a week I feed a small sheet of green or red seaweed.
I scrape the ATS screens once a week and thoroughly scrape the dump box. Lights on the ATS screens stay on all of the time.
I also have a combined GAC/GFO reactor which I currently completely change the media every other week. Media consists of 4 cups GAC, 2 cups high capacity GFO in a packed bed arrangement. This has controlled phosphate which used to be much higher. Currently at 0.17 ppm which I realize is still too high for hard corals.
Tank has been in operation for appr 15mo and I've learned several lessons along the way. But the nitrate issue that I'm currently experiencing is really confounding me. Any advice/recommendations are highly appreciated.
450 gal hex tank on main floor of my house
150 gal sump in the basement of my house (appr. 50 ft of dual PVC pipe between tank and sump)
Dual ATS system (dump style) above the sump in the basement
Apr. 100 fish
-- Foxface Rabbit, Magnifcent Rabbit, Scribbled Rabbit, 4 Hepatus Tang, 4 yellow tang, 2 Leopard wrasse, solorensis wrasse
-- Colony of dispar anthias
-- Colony of threadfin cardinals
-- 2 watchmen gobies + shrimp
-- pipefish
-- colony of blue damselfish
-- 4 clownfish + 4 red bubble tip anemones
Mostly soft corals (have not been successful with hard corals)
2 large clams
Tank is full of live rock with a 5" sand bottom.
I am feeding twice a day, each feeding consists of 2 rotations from autofeeder containing 80% flake (New Life Spectrum Optimum), 20% pellet (Sustainable Aquatics Hatchery Diet) food. I also feed frozen food appr every other day (Rod's). And a couple times a week I feed a small sheet of green or red seaweed.
I scrape the ATS screens once a week and thoroughly scrape the dump box. Lights on the ATS screens stay on all of the time.
I also have a combined GAC/GFO reactor which I currently completely change the media every other week. Media consists of 4 cups GAC, 2 cups high capacity GFO in a packed bed arrangement. This has controlled phosphate which used to be much higher. Currently at 0.17 ppm which I realize is still too high for hard corals.
Tank has been in operation for appr 15mo and I've learned several lessons along the way. But the nitrate issue that I'm currently experiencing is really confounding me. Any advice/recommendations are highly appreciated.