High NO3, Low PO4

[brad]

I have always ran high Nitrate and low or unmeasurable Phosphates (Hanna low range). Obviously I am behind on water changes, but have about 300 gallons total volume and need to tear my setup to move it to another room soon. Whenever I fix this with water changes, it is very hard to keep up with Nitrate, and I fall behind. I do dose vodka, and I do think it helps. I am considering a Sulfur reactor, dosing vinegar instead of vodka, actually dosing phosphates (since that is the limiting factor) and/or adding a refugium. Interestingly, I have never been able to keep plants alive in this setup (bubble tip anemones, Gorgonians and fish are thriving, some other hard and soft corals are surviving).

 

[brad]

I do not have a green algae problem. I do have a major corraline algae problem. You can barely see into the tank, even with me scraping at least once a week and 2 almost basketball sized Diademas and many smaller urchins munching away.

 

[tmz]

I fixed a similar problem with a diy sulfur dentrator( nitate form 80ppm plus to near 0 in 5 weeks ) on a 600 gallon system abut 5 years ago. Since the nitrates were lowered, vodka and vinegar have maintained thePO4 and NO3at low levels( PO4<.03ppm; NO3 0.2pmm) without the denitrator despite relatively heavy feeding.

 

[bertoni]

I might try the denitrator, and I'd get a second opinion on the nitrate kit, and get a nitrite reading. Nitrite will confuse nitrate test kits.

 

[brad]

How could I possibly have measurable nitrate in a 4 year old 300 gallon tank with neglected water changes and too much live rock? I agree running a sulfur dentrator or doing other things I am not doing might possibly do it.

I did add vinegar/kalkwasser as an experiment last night. I calculated 1 cup as the most I could add, but stopped adding about halfway as my skimmer went crazy. I have yet to remeasure, but this must have removed more than a week a vodka.

 

[tmz]

Ammonia and nitrite can pop up from time to time as degradation occurs. If so, just a little nitrite can skew some test to read high nitrate.

For 300 gallons , A max dose of about 140 ml vinegar daily or 1 /8th of that in vodka (17.5 ml) is normative for most users;tanks do vary. For kalk a max of 1/4tsp of diluted powder per 50 gallons of water volume should be safe in any given hour.( ie for 300 gallons,about 3 quarts of fully saturated kalk water ( 2tsps per gallon)