Nitrate Mitigation in FOWLR

[HumuhumuFan]

Hello everyone. I'm having trouble getting a handle on the nitrates in my 75g FOWLR. It has a 2.5" Rectangle Trigger and a 3.5" Yellow Tang and come hermits plus about 50 lbs of live rock. I feed them a mix of pellets and frozen plus nori sheets. I don't think I'm overfeeding, if anything I'm a little worried that the trigger looks thin. I got really busy with work for a while and my husbandry slipped. A few weeks ago, I tested the water and nitrate level was 80! (API Kit). I did a 30g water change and have been doing 2-3 10g water changes a week for the past 2 weeks. Nitrate still appears to be around 40-60. I use RO/DI and Instant Ocean. My RO/DI comes at 0-1 ppm, and I did a nitrate test on it just to make sure and it was 0.0. The tank also has a ReefOctopus HOB Skimmer. Should I just keep hammering on the water changes?

 

[Timfish]

You'll need to experiment with water changes and feeding to find a happy medium that keeps you nitrates at an acceptable level.

 

[Jekyl]

10% water changes don't do much. If nitrate was at 60, then a change would only get you to 54, then 49, then 44 etc... do 2, 30% changes per week until at desired levels. In mean time dosing nopox will start to help the system manage. Once at desired levels the nopox can help with stability. What's your phosphate at?

 

[kados]

@HumuhumuFan, for reference my 200g fowlr runs >75 on the Hanna Nitrate checker. It maxes at 75 so I know it's higher. I used to go nuts on keeping Nitrate low but on these semi- aggressive meat eater tanks (I have multiple puffers, triggers, Tangs, Harlequin Tusk etc. ) it will be a constant battle. I've done NoPox previously which works great, bio-pellets and all of that. What I've decided is keeping it simple like when I started 15 years ago. I don't plan on doing corals ever again bc I love big ol messy fish so I'm not worried with parameters being dialed in. I no longer dose NoPox or pellets. I run GFO and keep phosphates in check (bi-weekly test with Hanna) and 2 monthly 50% water changes for Nitrates. Most fish and especially the type of fish most people keep in a fowlr can tolerate higher nitrates. My goal is to keep algae minimal. I also run a 50w Pentair UV. Best part of fowlr is not micro managing parameters. Great info on this forum, the best around really.. but much of it is targeted at reef keepers. If your goal is fowlr then don't over think it.

 

[HumuhumuFan]

10% water changes don't do much. If nitrate was at 60, then a change would only get you to 54, then 49, then 44 etc... do 2, 30% changes per week until at desired levels. In mean time dosing nopox will start to help the system manage. Once at desired levels the nopox can help with stability. What's your phosphate at?

I am getting the ULR Phosphate Checker for Christmas. API kit reads between 0 and .25, not much help I know. That makes sense about the smaller changes being basically useless.

@HumuhumuFan, for reference my 200g fowlr runs >75 on the Hanna Nitrate checker. It maxes at 75 so I know it's higher. I used to go nuts on keeping Nitrate low but on these semi- aggressive meat eater tanks (I have multiple puffers, triggers, Tangs, Harlequin Tusk etc. ) it will be a constant battle. I've done NoPox previously which works great, bio-pellets and all of that. What I've decided is keeping it simple like when I started 15 years ago. I don't plan on doing corals ever again bc I love big ol messy fish so I'm not worried with parameters being dialed in. I no longer dose NoPox or pellets. I run GFO and keep phosphates in check (bi-weekly test with Hanna) and 2 monthly 50% water changes for Nitrates. Most fish and especially the type of fish most people keep in a fowlr can tolerate higher nitrates. My goal is to keep algae minimal. I also run a 50w Pentair UV. Best part of fowlr is not micro managing parameters. Great info on this forum, the best around really.. but much of it is targeted at reef keepers. If your goal is fowlr then don't over think it.

I have a decent light on it, so I was going to try to add a few corals. I have a reef (20g long), but space is already at a premium in that tank. I would love the be able to move some of my endlessly growing orange Monti into the tank, and maybe some xenia and GSP. Something to compete with the GHA for space on the rocks. Long-term I plan on moving the 20g reef into the 75g, and moving the tang and trigger into a 180g I'm saving for. Maybe forgetting about the coral and embracing the FOWLR lifestyle is the way to go until the tank swap happens.

Thank you all for the input.