How to get Phosphates down

[Silverbeachfish]

I have been using BRS GFO for years. It works for me in a small sump reactor. Just change it out every 4-5 weeks so your phosphates level stay stable.

 

[FindingNem0]

Raise the nitrate and the phosphate may come down on its own. I use neonitro in my tank to keep nitrates up. Another option is to dose ammonia via ammonium chloride and let the bacteria convert it to nitrate. Corals can benefit more directly from ammonia, but it is a bit more DIY than the neonitro option and potentially more dangerous to livestock if not done properly.

So for Ammonium chloride, Dr tims Ammonia will work yah? Been told by multiple sources now, that dosing ammonia is probably better then straight nitrate, just more risky if done wrong.

 

[Randy Holmes-Farley]

So for Ammonium chloride, Dr tims Ammonia will work yah? Been told by multiple sources now, that dosing ammonia is probably better then straight nitrate, just more risky if done wrong.

It will work, but I'd personally get a food grade material. I do not know what Tim uses and it is not intended to be used every day in an existing reef tank, so may legitimately have different purity requirements. I also think ammonium bicarbonate is a better bet for most people since ammonium chloride will deplete alkalinity.

DIY Ammonia dosing for low nitrate systems

Some reef aquaria have chronic low nitrogen availability. One indicator is very low nitrate. Nitrate dosing is a fine remedy, but it is possible that ammonia dosing may be more beneficial for some organisms since ammonia can be energetically easier to assimilate than is nitrate. For this...

www.reef2reef.com

 

[Reef Puncher]

That seems excessive, IMO. 0.5 ppm phosphate has been shown to reduce coral calcification rates.

I recommend 0.02 to 0.1 ppm, with values above that range better than below it.

That guy from fauna marin, leo? Cant remember his name, the spokesman guy, said 0.4 is ideal, so maybe thats where he got that number from. i run my tank around that. chasing 0.01 is sooo hard. i really dont want 0.00 for fear of dino, and i dont want 0.1 as its too high, so aiming for 0.03-0.04 seems easiest that way if it fluctuates a little lower or higher your ok.

 

[Formulator]

That guy from fauna marin, leo? Cant remember his name, the spokesman guy, said 0.4 is ideal, so maybe thats where he got that number from. i run my tank around that. chasing 0.01 is sooo hard. i really dont want 0.00 for fear of dino, and i dont want 0.1 as its too high, so aiming for 0.03-0.04 seems easiest that way if it fluctuates a little lower or higher your ok.

0.1 is not too high. That should be your target IMO.

 

[Lavey29]

I’m not saying they aren’t, and not everyone wants or needs to maximize growth anyway.

I actually wanted to ask you a question about this area. If you have elevated phosphate levels in your tank will maintaining elevated nitrates levels help lower phosphates or keep them from rising further? Essentially will keeping a sufficient ratio of nitrates to phosphate even if elevated well past recommended guidelines keep both numbers consistent and still be beneficial for the tank long term? I realize a tank can only process so much nitrates and phosphate as stocking and filtration allows and anything over that is excess and increases numbers.

But in my situation with elevated phosphate levels, I am finding that maintaining elevated nitrates levels helps keep the phosphate number consistent and the tank thrives.

 

[Formulator]

I actually wanted to ask you a question about this area. If you have elevated phosphate levels in your tank will maintaining elevated nitrates levels help lower phosphates or keep them from rising further? Essentially will keeping a sufficient ratio of nitrates to phosphate even if elevated well past recommended guidelines keep both numbers consistent and still be beneficial for the tank long term? I realize a tank can only process so much nitrates and phosphate as stocking and filtration allows and anything over that is excess and increases numbers.

But in my situation with elevated phosphate levels, I am finding that maintaining elevated nitrates levels helps keep the phosphate number consistent and the tank thrives.

I have found the same. In fact, in my recent battle with extremely elevated PO4, I was able to lower my PO4 from 2.0 to 1.0 with nitrate dosing alone before I had to implement GFO to get it the rest of the way down to 0.1 ppm. I still have to dose daily to keep the nitrates up. Its almost as if there are denitrifying bacteria still present from a carbon dosing program I discontinued several years ago, and apparently a carbon source hanging around. Or perhaps my corals and chaeto consume it, but the level of consumption is near 2 ppm/day nitrate which seems like a lot without help from bacteria.

 

[Badboyan93l]

That seems excessive, IMO. 0.5 ppm phosphate has been shown to reduce coral calcification rates.

I recommend 0.02 to 0.1 ppm, with values above that range better than below it.

True indeed. When my phos rises from 0.1 to 0.4 I don’t see the white growth rim on my montis once I lower it back down the white rim re-appears

 

[Randy Holmes-Farley]

That guy from fauna marin, leo? Cant remember his name, the spokesman guy, said 0.4 is ideal, so maybe thats where he got that number from.

I have never seen evidence that 0.4 ppm phosphate is ideal, and it certainly is not a commonly discussed number.

 

[Randy Holmes-Farley]

I actually wanted to ask you a question about this area. If you have elevated phosphate levels in your tank will maintaining elevated nitrates levels help lower phosphates or keep them from rising further? Essentially will keeping a sufficient ratio of nitrates to phosphate even if elevated well past recommended guidelines keep both numbers consistent and still be beneficial for the tank long term? I realize a tank can only process so much nitrates and phosphate as stocking and filtration allows and anything over that is excess and increases numbers.

Not unless the N availability (from nitrate, ammonium, urea, organics, etc.) was otherwise so low that it was growth limiting to organisms.

Certainly, 100 ppm nitrate is not going to allow phosphate to drop faster than is 10 ppm nitrate in a typical reef tank (IMO).

 

[Spare time]

Given the typical error range of any of the testers how can you be comfortable at .03 number? Could be 0 right?

Depends on the test. For my salifert on my nano tank, all I need is a little tint of color. This tank gets fed heavily. For a hanna checker, 0.03ppm is the minemum I allow since it is +/-0.02 if the test is performed perfectly.

 

[Lavey29]

Not unless the N availability (from nitrate, ammonium, urea, organics, etc.) was otherwise so low that it was growth limiting to organisms.

Certainly, 100 ppm nitrate is not going to allow phosphate to drop faster than is 10 ppm nitrate in a typical reef tank (IMO).

Ok that is what I was wondering...thank you

What are your thoughts on the 100 : 1. Ratio for nitrates to phosphate? Essentially 10 nitrates to .1 phosphate? Is this the perfect balance?

 

[Randy Holmes-Farley]

Ok that is what I was wondering...thank you

What are your thoughts on the 100 : 1. Ratio for nitrates to phosphate? Essentially 10 nitrates to .1 phosphate? Is this the perfect balance?

IMO, ratios don’t make much sense. There are plenty of values of nitrate and phosphate that fit that or any other ratio which are both too high or both too low.

IMO, it is never wrong to give absolute targets, such as 2-10 ppm nitrate and 0.03 to 0.1 ppm phosphate.