Dosing Nitrates and Phosphates

[Reef of Fillory]

I was dosing nitrates [zero'd out - and zero'd out phosphates as well] and I decreased my refugium light period and the phosphate came up as I continued to dose nitrates. I also have always overfed, and I ran my skimmer with the collection cup draining back into the tank. I even overstocked my tank and couldn't get nitrate to raise. Once I shortened by refugium time enough, they began to balance and I could control nutrient levels by upping or dropping the light time.

Everyone has issues with too high of nutrients, but i've had too low since the start in this hobby =S

 

[DiZASTiX]

In general, the algae growth is one main reason why we used to recommend lower nitrate and phosphate than seems the trend today, with added other foods to help make up for the deficit in corals (e.g., amino acids, target feeding of corals, etc.).

I have a similar issue. My phosphates are undetectable with a Hanna Checker. However, my Nitrates are over roughly 20 ppm. However, in my situation, I seemed to have generated some sort of mini-cycle. I've also never used GFO, but do use a Chaeto Reactor, so this isn't exactly the same example.

Would I need to reduce nitrates while increasing phosphates?

 

[Lasse]

I have a similar issue. My phosphates are undetectable with a Hanna Checker. However, my Nitrates are over roughly 20 ppm. However, in my situation, I seemed to have generated some sort of mini-cycle. I've also never used GFO, but do use a Chaeto Reactor, so this isn't exactly the same example.

Would I need to reduce nitrates while increasing phosphates?

If you rise your phosphates you will probably by automatic lower your NO3 (however "rise" is not a good word because if you ad some PO4 - its not sure that your measured PO4 will rise - it will probably bound together with your excess NO3 in more Chaeto biomass)

Sincerely Lasse

 

[Randy Holmes-Farley Verified Community Expert]

I have a similar issue. My phosphates are undetectable with a Hanna Checker. However, my Nitrates are over roughly 20 ppm. However, in my situation, I seemed to have generated some sort of mini-cycle. I've also never used GFO, but do use a Chaeto Reactor, so this isn't exactly the same example.

Would I need to reduce nitrates while increasing phosphates?

I'm not sure what you mean by "need to", but it might well happen if the chaeto grows faster.

 

[ecam]

I was reading through this thread... I would like to start dosing but what is the product that should be ordered on amazon or purchased at HD or Lowes.....

for potassium nitrate
@Randy Holmes-Farley

 

[DirtDiggler2823]

The dry phosphate compounds, how are they mixed and dosed? I'd rather use those than buying neophos or something else like it. I don't use GFO, but I do run a refugium. My nitrates at typically between 5-10 ppm, but I can never get phosphate into a level that's detectable with my sailfert test kit. I've tried overfeeding and while I was able to get some phosphate, my nitrates went through the roof.

 

[Lasse]

I use pure KH2PO4 - 4.3 grams in one liter of RO water as stock solution. 1 ml of this will rise the concentration of PO4 with around 0.03 ppm/100 liter of aquarium water. If you have read zero for a prolonged period - watch up for the "ketchup effect". Nothing, nothing, nothing and suddenly a fast rise.

For nitrate - I use KNO3 or NaNO3 80 grams into 1 liter RO water. 1 ml of this give a rise of NO3 around (read around - it differ slightly between NaNO3 and KNO3) 0.5 ppm/100 liter aquarium water.

Sincerely Lasse

 

[Scrubber_steve]

The dry phosphate compounds, how are they mixed and dosed? I'd rather use those than buying neophos or something else like it. I don't use GFO, but I do run a refugium. My nitrates at typically between 5-10 ppm, but I can never get phosphate into a level that's detectable with my sailfert test kit. I've tried overfeeding and while I was able to get some phosphate, my nitrates went through the roof.

Salifert is not a suitable test kit for low range phosphate. Get Red Sea Pro test kit.

 

[DirtDiggler2823]

Salifert is not a suitable test kit for low range phosphate. Get Red Sea Pro test kit.

I'm about to get an Hanna ULR Phosphorus checker and just use the conversion table.

 

[DirtDiggler2823]

I use pure KH2PO4 - 4.3 grams in one liter of RO water as stock solution. 1 ml of this will rise the concentration of PO4 with around 0.03 ppm/100 liter of aquarium water. If you have read zero for a prolonged period - watch up for the "ketchup effect". Nothing, nothing, nothing and suddenly a fast rise.

For nitrate - I use KNO3 or NaNO3 80 grams into 1 liter RO water. 1 ml of this give a rise of NO3 around (read around - it differ slightly between NaNO3 and KNO3) 0.5 ppm/100 liter aquarium water.

Sincerely Lasse

Nitrates have never been an issue, just phosphate. What brand KH2PO4 do you use?

 

[lilgrounchuck]

Seachem makes a product called Flourish that is an easy way to dose phosphate. It's designed for freshwater planted tanks but works great for dosing a reef tank. I'm currently using it.

This is a great source of lab grade sodium nitrate. Very inexpensive and this bag will last a long, long time.

They have nitrate and phosphate flourish chems. I use them for my planted tank

 

[Lasse]

I'm about to get an Hanna ULR Phosphorus checker and just use the conversion table.

Take a closer look at HI774. However - the Hanna checker not always show you the truth in this low range. I have one that show 0.12 ppm when TRITON says 0.038 ppm PO4. But now I know - and use it in order to see if the PO4 waste concentration going up or down. (waste - not used amount) I dose around 0.06 ppm each day

Nitrates have never been an issue, just phosphate. What brand KH2PO4 do you use?

I live in Sweden and I order my chemicals from a site dealing with PMDD dosing for planted tanks

Any food grade quality will work. You can use lab grade too

Sincerely Lasse

 

[DirtDiggler2823]

Take a closer look at HI774. However - the Hanna checker not always show you the truth in this low range. I have one that show 0.12 ppm when TRITON says 0.038 ppm PO4. But now I know - and use it in order to see if the PO4 waste concentration going up or down. (waste - not used amount) I dose around 0.06 ppm each day


I live in Sweden and I order my chemicals from a site dealing with PMDD dosing for planted tanks

Any food grade quality will work. You can use lab grade too

Sincerely Lasse

Thank you for your response. I will look at getting my own so I can dose as well.

 

[Randy Holmes-Farley Verified Community Expert]

Nitrates have never been an issue, just phosphate. What brand KH2PO4 do you use?

As mentioned, any food grade is fine.

That said, I’ve never understood why people are using potassium salts rather than sodium salts. Maybe it’s a carryover from freshwater lore, but at least when dosing nitrate, there is a risk of potassium steadily rising. That’s not so concerning with phosphate because so much less is dosed.

 

[DirtDiggler2823]

As mentioned, any food grade is fine.

That said, I’ve never understood why people are using potassium salts rather than sodium salts. Maybe it’s a carryover from freshwater lore, but at least when dosing nitrate, there is a risk of potassium steadily rising. That’s not so concerning with phosphate because so much less is dosed.

So you're recommending sodium salts for this purpose?

 

[Lasse]

As mentioned, any food grade is fine.

That said, I’ve never understood why people are using potassium salts rather than sodium salts. Maybe it’s a carryover from freshwater lore, but at least when dosing nitrate, there is a risk of potassium steadily rising. That’s not so concerning with phosphate because so much less is dosed.

In my case - I use KNO3 because my during the first years of my new aquarium it normally consume potassium. I had to restore the value to the 400 ppm after each TRITON test in the beginning. Because that you add around 0.39 gram K to each gram of NO3 and if you like me use a lot of NO3 - if I calculate the dose in ppm in my 300 l aquarium between my last two TRITON test - I have dosed 26.1 gram pure NO3. -> I have also dosed around 21.5 gram K. It should have rise my K with around 71 ppm. The TRITON test show a rise from 422 ppm to 439 ppm during the same period - it means a rise of 17 ppm. My consumption during this time can be calculated at least to be around 54 ppm. However - 439 ppm is a little bit to high for me in the long run and if it will continue to rise - toxic levels (for fish) can be reached. I will change to dose NaNO3 for a while till my numbers of K is below 400 ppm. In my old aquarium I had a lot of fish that die in a way that indicate toxic substances in the water. K in that water was around 660 ppm

​

The first sample point is from my old aquarium. The second point (and all of the rest) is from my new aquarium

For the book - I have a chaeto refugium.

Sincerely Lasse

 

[Randy Holmes-Farley Verified Community Expert]

So you're recommending sodium salts for this purpose?

Assuming you can get them adequately pure, yes.

 

[DirtDiggler2823]

Assuming you can get them adequately pure, yes.

I went with this one

 

[motortrendz]

@Randy Holmes-Farley what is your recipe and dosing recommendations
For sodium nitrate?

 

[zalick]

@Randy Holmes-Farley what is your recipe and dosing recommendations
For sodium nitrate?

Also looking. I thought spectracide stump remover, pure potassium nitrate, was acceptable! I just bought some..... :/