Sky high phosphates and 0.75 nitrates

[CoralWealth]

Your tank looks good and you have no problems. Chasing numbers means to create problems and most likely, if you continue like you suggested, you will have a lot of problems soon, like hair algae and cyanobacterial growth, slow growing or dying corals and maybe more.

If it is really phosphate and not phosphorus 90 µg/l (ppb) is all but sky high, it is only 0.09 ppm which in my eyes is in the optimum range.

Nitrate is most likely so low because you have growing corals and a good tank biology. This keeps nitrogen in flow and in the forms of ammonium, amino acids and other organic nitrogen compounds. Chasing numbers with nitrate may also create problems.

If my phosphate was only 0.09 I wouldn’t be chasing it at all. I use the Hanna ulr and 90 is 0.3 phosphates, not sure where you got 0.09 from but I wish my phosphates were there.

Why would lowering my phosphate from 0.3 to below 0.1 be a bad thing and cause all those things you just mentioned? Doesn’t make much sense to me. I thought the imbalance between phosphate and nitrates would be bad. Considering my nitrate is under 0.5 using Red Sea test kit and phosphate is 0.3

 

[Hans-Werner]

Sorry, you wrote that the Hanna ULR shows 90 phosphate and I know form their aquaculture photometer that the ULR gives the results in µg/l (ppb). We can switch the photometer from phosphorus to phosphate. That is why I asked whether you are really talking about phosphate or about phosphorus.

Something like an imbalance between phosphate and nitrate does not really exist. If something like that exists it has to be an imbalance between phosphate and nitrogen compounds. With low phosphate concentrations the complete N needs can be fulfilled by ammonium, urea and amino acids present in the water and excreted by fish, so you don't really need nitrate at all. Nitrate is the end product of nitrification and if it occurs in the water it shows there is a surplus of ammonium and/or urea, otherwise it would not be formed or it would be taken up, reduced and incorporated into amino acids by algae including zooxanthellae.

 

[CoralWealth]

Sorry, you wrote that the Hanna ULR shows 90 phosphate and I know form their aquaculture photometer that the ULR gives the results in µg/l (ppb). We can switch the photometer from phosphorus to phosphate. That is why I asked whether you are really talking about phosphate or about phosphorus.

Something like an imbalance between phosphate and nitrate does not really exist. If something like that exists it has to be an imbalance between phosphate and nitrogen compounds. With low phosphate concentrations the complete N needs can be fulfilled by ammonium, urea and amino acids present in the water and excreted by fish, so you don't really need nitrate at all. Nitrate is the end product of nitrification and if it occurs in the water it shows there is a surplus of ammonium and/or urea, otherwise it would not be formed or it would be taken up, reduced and incorporated into amino acids by algae including zooxanthellae.

Oh okay, makes sense. Thank you for that! I still think that slowly lowering my phosphates from 0.3 to ideally around 0.05 would be best, but I honestly will be happy with anything below 0.1

 

[Hans-Werner]

Yes, 0.3 ppm phosphate would be a little high, also for my taste. I would at least try to get below 0.15 ppm phosphate.
How do you add calcium?

 

[CoralWealth]

Okay, I will do it slowly with the phosphate RX.

I use a calcium reactor and kalkwasser for my dosing. I also have a KH Guardian that tests every 3 hours to check my alkalinity, I usually confirm its results with the salifert alk and aquaforest alk test kit about 2 times a week and it is always spot on.

 

[Hans-Werner]

If calcium reactor means coral rubble/CO2 reactor this could be the source of your phosphates. Coral rubble always contains some phosphate which is dissolved and washed into the aquarium by the running of the reactor. This would also explain why the phosphate is in a high ratio to nitrate

 

[CoralWealth]

If calcium reactor means coral rubble/CO2 reactor this could be the source of your phosphates. Coral rubble always contains some phosphate which is dissolved and washed into the aquarium by the running of the reactor. This would also explain why the phosphate is in a high ratio to nitrate

Yes that is what it means and I have ran that for years, only recently has phosphate been high. I have a constant stream going through it, I will always use a calcium reactor. My corals have taken off since I added that awhile back.

 

[Hans-Werner]

My corals have taken off since I added that awhile back

A result of the phosphate supply.

 

[CoralWealth]

A result of the phosphate supply.

Haha maybe.

 

[Hans-Werner]

Serious, I am quite sure it is. You will notice it more or less when you lower phosphate concentration, so be careful. That is why I warned you from chasing numbers.

 

[CoralWealth]

Serious, I am quite sure it is. You will notice it more or less when you lower phosphate concentration, so be careful. That is why warned you from chasing numbers.

I never had that problem in the past couple years though, but I will watch it. Only number I am "chasing" is lowering my phosphates from 0.3, I don't think that is really chasing a number but instead it would be beneficial for my tank. Especially with all SPS and doing it very slowly.

 

[Hans-Werner]

SPS are the ones that respond most positive to phosphate and most negative to low phosphate concentrations. Keep an eye on them.

 

[CoralWealth]

SPS are the ones that respond most positive to phosphate and most negative to low phosphate concentrations. Keep an eye on them.

I will, however I have had better PE during the day and at night ever since I started adding phosphate RX last week.

 

[Hans-Werner]

Ok, everything has its limits and enough is enough (phosphate).

 

[Belgian Anthias]

Carbon, nitrate, and phosphate are used up by typical exporters in different amounts. If you're primarily exporting these via skimming and waterchange, then you'll lower the amount of phosphate the least, because bacteria that is skimmed out will utilize carbon, and nitrate way more than phosphate. so over time phosphate numbers will slowly rise without a few large water changes to significantly dilute the phosphate or media like GFO or lanthanum and a very fine filter for removing lanthanum.

Strange as skimmers exporting bacteria remove phosphorus and nitrogen in natural proportions. By the way, live bacteria are not skimmed, they may be exported on the foam. As most nitrogen enters the system by the gills, and skimmers do not skim nitrate, enough nitrate should be avaiable to consume phosphorus. Normally growth is limited by other building material availability.

 

[Stigigemla]

In a tank with live rock, sand or another medium for denitrifying bacteria nitrate will be consumed by bacteria and converted to nitrogen that will be aerated out. And there will be a phosphate plus in the tank.
And live bacteria can be skimmed out - anyone who has been using a carbon source has seen that.
Practically all my customers that use a carbon source also has some GFO in the sump to keep the phosphate value down.