Sps keepers with higher nitrate and phosphate level

tom obrecht

Active member
I'm curious if anyone is currently keeping acros with higher phosphate and/phosphate? I know nitrates are perhaps less critical but here are my current questions.
my system is ~2 years old. Started with dry rock and bare bottom. After 1 1/2 years I had what seemed like a lack of biodiversity which would be understandable with the start of dry rock and bare bottom. I was adding bottled bacteria's of different strains and did have some bio bricks from a past system which I thought would be enough to seed the dry rock. After 1 1/2 years I was having difficulty keeping a wide range of sps. Some pieces did ok while others died. In an attempt to get things rolling ( and patience running out!) I added bagged (live ) sand. This seemed to help for a bit but then Cyano and Dinos hit hard. Phosphate and nitrates were zero or at least unreadable on my tests. I started adding nitrate and phosphate to help raise levels to readable levels. Without luck I ended up dosing chemiclean and within a couple weeks the tank looked as clean as it has since the day I started.
Now to my question. Since adding chemiclean my nitrates stay steady at 25 and phosphate at .15 which I realize is above the normal levels. However the tank continues to run clean. I have been dosing phytoplankton daily without issues. I'm curious what everyone feels maybe the reason some sps do well and others fail? Plating pieces like caps seem to do well while some acros stn. I'm thinking it maybe the higher phosphate and nitrate but hesitate to lower thinking Cyano may return. Thoughts?


There could be a lot more to it than just nitrate and phosphate levels. I don't want to be that guy but what are your lights/flow/other parameters? My tank is about 15 months old, full of sps and my birdsnest and montipora colonies all grow very well. A lot of acros are taking their time growing but are coloring up nicely I noticed. The largest acro colony is about 9". My phosphate and nitrate tend to stay around 0.1 and 20 but I focus on consistent water changes and dosing to keep my parameters as stable as possible. Personally I have seen tanks with higher nitrate and phosphate levels that keep sps well and so far I've had good success with it. I've heard that higher levels can color up corals but it can also lead to algae outbreaks.

How many sps pieces have you tried? Acros can be picky but you can start out with easier acros like a green slimer. Caps and branching montis as well as birdsnest don't need quite as consistent parameters as acros so it might be a good idea to try some of those if you haven't yet already.

Bob Nell

New member
I had a similar experience only my reef had been running successfully for 10+ years. I could not put my finger on the cause but think my nitrate creeped up in the 30 to 40 range, difficult to verify on the test kit I was using. I also use gfo, which keeps phos at .1 to .15. I did not experience cyano or dinos. I have worked to reduce nitrates and now reads about 20 to 25 using a different test kit and have added frags, which have been doing well. I am hoping to get nitrates to 5 or so. Check with vendors because it seems most are at that or lower.


New member
Ppl are having some good success with specific species (mostly tenuis). They are mostly if not all under heavy led with lower par. I don't agree with this method and feel this is a confusion of food availability vs consumption.