LR has been cycling for ~2 weeks - is it safe to add a fish or two?

[kerinin]

I'm starting up a Fluval m90 (36 gallon AIO) with about 40lb of "cured" fiji and ~3" oolitic aragonite substrate. I have an assortment of macroalgae and a constant light in one of the filter spaces in back as a zooplankton food refugium. The tank has been cycling for almost two weeks and I'm wondering if I should add a fish or two. Ammonia & Nitrite levels are zero, but Nitrates are around 40ppm. Yesterday I added a strawberry conch to eat up some of the diatom bloom that's been going on for a day or two.

Is it safe to add a smallish fish? Is it helpful to add a smallish fish? I'm not sure if I should be more concerned about nitrate levels being unhealthy or ammonia levels dropping and reducing the bacterial population. Or neither.

Does anything else jump out as a bad idea?

 

[Shewillbemine]

That's too much nitrates. I'd do a couple water changes and test for all 3 again until the ammonia and nitrites are still zero and nitrates dropped lower.

 

[thegrun]

Did you ever have an ammonia spike? It's possible that you will not have a cycle with the cured live rock, but I would have added some pure ammonia to drive the level up to 2ppm and see how long it took to drop back to zero BEFORE adding any livestock. You do not need to worry about feeding the bacteria, the bacteria that breaks down fish waste has been shown to live up to a year without any food. Honestly I think you are rushing things a bit by adding the conch, I would wait at least another week before adding fish.

 

[kerinin]

The highest ammonia level I recorded was 0.6ppm. Nitrites maxed out at at 5ppm and have been 0 for a few days.

Is it worth adding some ammonia now?

 

[Irishman360]

You would kill your conch by adding pure ammonia in it now IMO.

 

[thegrun]

I agree at this point I would not add ammonia. Wait another week or two, if you do not see any signs of ammonia or nitrites you could then slowly start to add fish, although I would strongly recommend quarantine them first.

 

[thelawnwrangler]

I'm starting up a Fluval m90 (36 gallon AIO) with about 40lb of "cured" fiji and ~3" oolitic aragonite substrate. I have an assortment of macroalgae and a constant light in one of the filter spaces in back as a zooplankton food refugium. The tank has been cycling for almost two weeks and I'm wondering if I should add a fish or two. Ammonia & Nitrite levels are zero, but Nitrates are around 40ppm. Yesterday I added a strawberry conch to eat up some of the diatom bloom that's been going on for a day or two.

Is it safe to add a smallish fish? Is it helpful to add a smallish fish? I'm not sure if I should be more concerned about nitrate levels being unhealthy or ammonia levels dropping and reducing the bacterial population. Or neither.

Does anything else jump out as a bad idea?

I have the same tank hope to fill it with water and live rock this weekend. Did you change any of the equipment?

 

[kerinin]

Nope, I just let it run for while and did some larger water changes. Nitrates are down to about 5ppm now. I have a firefish and a couple little corals, everything seems to be going fine.

Love the tank