The Relationship Between Phosphate and Nitrate..

[skyking]

Been doing some troubleshooting on why my coral slowly dies. The 1st 4-5 years or so everything was doing great and the parameters were stable. Here in the last year I've ever so SLOWLY lost monti, clove, xenia, and various LPS's and SPS's. So I decided to do some troubleshooting and recently bought a variety of test kits and found that my phosphates were 0.5. All other parameters were in check. I added some GFO into my reactor and tested my phosphates and nitrates the following day. Phosphates decreased to 0.2 but my nitrates went from 0 to 40-50. (Red Sea Test Kits). Also, Ive noticed that my protein skimmer is not producing as much as it did yesterday. So, my question is, do phosphates keep nitrates in check? What do I need to do to bring the nitrates back down to an acceptable level while keeping my phosphates low? Thanks for any and all advice,
Jeff

 

[bhodges82]

Phosphate and nitrate are used by corals and algae in proportion to each other according to the redfield ratio. When you reduced the available phosphate the nitrate could not be up taken by organisms because the ratio of each nutrient available is not proportionate to what the organism is accustomed to.

Many people that run only gfo tend to have nitrate issues because they disturb the balance of nutrients by only removing phosphate. I prefer a natural export method via macro algae or through water change because both methods take out nutrients in equal ratios.

 

[Dmitri]

I found this chart to be helpful into understanding on relationship between phosphates and nitrates plus effects on algae growth.

 

[ichthyoid]

Been doing some troubleshooting on why my coral slowly dies. The 1st 4-5 years or so everything was doing great and the parameters were stable. Here in the last year I've ever so SLOWLY lost monti, clove, xenia, and various LPS's and SPS's. So I decided to do some troubleshooting and recently bought a variety of test kits and found that my phosphates were 0.5. All other parameters were in check. I added some GFO into my reactor and tested my phosphates and nitrates the following day. Phosphates decreased to 0.2 but my nitrates went from 0 to 40-50. (Red Sea Test Kits). Also, Ive noticed that my protein skimmer is not producing as much as it did yesterday. So, my question is, do phosphates keep nitrates in check? What do I need to do to bring the nitrates back down to an acceptable level while keeping my phosphates low? Thanks for any and all advice,
Jeff

If I understand this post correctly, then I seriously doubt that your nitrate went from zero to between 40 & 50, in just one day!

Something else has got to be going on here? Are you sure that you ran the test correctly?

 

[skyking]

Thanks for the reply guys. Yes. Im sure I ran the test correctly. I ran it 3 separate times using 2 different mediums. Sump and ATO water reservoir. I did a 30% water change this morning and retested. Phosphates still at .2 and nitrates at 40-50.

 

[FutureInterest]

Imo, you should get an icp test done. That level of nitrates and phosphates are high but not nearly enough to kill all the coral you listed. There is likely a concentration of some heavy metals or some critical deficiency.