Readings for phosphate and dkh

[Geiger31]

Recently went out to buy better testing equipment for my nano tank and purchased the Hanna instruments for testing phosphate ulr and alkalinity. My reading last came back at .52 ppm for phosphate and 12.8 for dkh. Are these normal readings? I’m more concerned of the phosphate reading right now.

 

[Spare time]

That would be pretty high for phosphate. I find most people do well under 0.1 (and above 0.00). Just make sure you keep the vial clean from finger prints and insert it the same way for each test. As for alk, 12.8 is the upper limit (the highest salt mix is at 13). You won't have problems with alk that high so long as you provide enough light, flow, and some amount of nitrate and phosphate or frequent coral feeding (typically salts with high alk also run higher calcium and magnesium). I keep my alk around 12 ish.

 

[Geiger31]

That would be pretty high for phosphate. I find most people do well under 0.1 (and above 0.00). Just make sure you keep the vial clean from finger prints and insert it the same way for each test. As for alk, 12.8 is the upper limit (the highest salt mix is at 13). You won't have problems with alk that high so long as you provide enough light, flow, and some amount of nitrate and phosphate or frequent coral feeding (typically salts with high alk also run higher calcium and magnesium). I keep my alk around 12 ish.

Just checked it again, without adding or taking anything out of the tank and it came back at .47ppm. I’ll leave it alone tonight then maybe water change tomorrow and add some type of chemical to filter sponge to lower the phosphate.

 

[Randy Holmes-Farley Verified Community Expert]

Water change won't help much for phosphate. Even 100% won't do it.

It's not a disaster, but I'd look to lower it over time. A binder such as GFO is an OK choice.