High Po4, low No3

[Falcar]

Good morning all:

I had neglected my tank for about a year, and recently have been working on getting it back in good shape.

I've got the display clear of hair algae and everything is starting to look good. All my parameters look good except PO4, I'm looking at a > .9 on the hanna ULR (it's pretty blue too!) but nitrate is only around 5.

I've brought the level down to about .6 with Lanthanum, but didn't want to do too much too fast, and now it's back up over .9. I'd like to avoid GFO if possible, but what are my other options to this situation? In the past I've always dealt with elevated nitrates instead of phosphates. I've also done several large water changes, mostly to replenish any trace elements that might have been missing.

Thoughts would be appreciated!

 

[Lavey29]

Is it a fowler or do you have corals? Raising nitrates to 15 will help lower phosphates also. Half dosing lanthium chloride is safe for walking it down. You need to correct the source of the phosphates also.

 

[Randy Holmes-Farley Verified Community Expert]

FWIW, I do not think 5 ppm nitrate is low

 

[Falcar]

Is it a fowler or do you have corals? Raising nitrates to 15 will help lower phosphates also. Half dosing lanthium chloride is safe for walking it down. You need to correct the source of the phosphates also.

It does have some corals, nothing too crazy, softies and LPS

 

[Falcar]

FWIW, I do not think 5 ppm nitrate is low

I guess I should have said in comparison to the phosphate!

 

[Lavey29]

FWIW, I do not think 5 ppm nitrate is low

I wouldn't say it's low either just not ideal for LPS corals in his tank and possibly limiting his phosphate reduction effort.

 

[Randy Holmes-Farley Verified Community Expert]

I wouldn't say it's low either just not ideal for LPS corals in his tank and possibly limiting his phosphate reduction effort.

I'd dispute the LPS issue, but higher is also OK. I agree it will limit balanced phosphate reduction, such as by macroalgae, but not a binder such as GFO.

 

[Falcar]

Slowly but surely my tank is starting to improve with these levels..Currently sitting at 2.5 nitrate and .5 phosphate. Still high, but coming down slowly but surely!

 

[dr_vinnie_boombatz]

Slowly but surely my tank is starting to improve with these levels..Currently sitting at 2.5 nitrate and .5 phosphate. Still high, but coming down slowly but surely!

You're doing great, just for some comparison from my favorite coral shop (.81 PO4 and NO3 16.4, in the video they discuss the higher levels)

 

[PharmrJohn]

With corals, the nitrate and phosphate ratio is important. Try to keep nitrate at about 1 and phosphate at about 0.1. With increased Phosphate comes the inhibition of coral growth.

 

[Randy Holmes-Farley Verified Community Expert]

With corals, the nitrate and phosphate ratio is important. Try to keep nitrate at about 1 and phosphate at about 0.1. With increased Phosphate comes the inhibition of coral growth.

I don’t agree about a ratio being important, but more specifically, I think nitrate at 1 ppm is too low for some aquaria unless they are high input and high export systems with a lot of potentially available ammonia.