What should I keep my PO4 at?

WIReefer · Jun 1, 2020

So just a question for you guys I’m starting to get more into acros have had Easy sps corals for some time now, some beginner acros, wanting to get into more high end ones just a little background of the tank it’s a 55 with a 32 gallon sump been running for around 14 months light running a 48 6 bulb Sunpower, I switched to tropic marine salt about two months ago I dose a small amount of BRS Kalk with a kalkstirrer to keep Alk around there. I try to keep my Alk around 7.6-8. My question is what should I keep my PO4 around to have success with that Alk level?

Parameters tested last night.

Salinty: 1.025 Milwaukee
PH: 8.12 Apex
Temp: 78 Apex
Alk: 7.6 Hanna
Phosphates: 0.04 Hanna
Calcium: 440 Hanna

SCReef'n · Jun 1, 2020

Looks good to me. I shoot for <.05 but detectable.

WIReefer · Jun 1, 2020

SCReef'n said:
Looks good to me. I shoot for <.05 but detectable.

Okay, for the longest time I had undetectable which I new wasn’t good I started feeding more and it’s working.

Crustaceon · Jun 1, 2020

I’d keep it between .05 -.08 ppm. I like having a little margin for safety because acros can’t seem to stand even momentary stints at zero phosphates and always start to stn when that happens in my system. I keep a bottle of flourish phosphorus on hand and make small adjustments as needed after running my hanna phosphate checker.

MERKEY · Jun 1, 2020

From my what I've gathered the lower the alk the lower the nutrients can be. Ive seen tanks run at .1-.2 that are amazing....but the alk in those tanks are 9-10.

Just watch out that you don't bottom N or P out...and definitely dont bottom them out together lol

Also be careful over feeding to build N and P. Once it gets into the sand and rocks it will leach out like crazy and could start a spike of either of those nutrients.

With alk where it is in your tank I agree with the above that .05 is a good place for you to have it.