Dosing Nitrates - how much?

[MmmmBalf]

Hello all,

My Nitrates have been at zero for some months now, with PO4 reading 0.02ppm - 0.04ppm. I had a huge problem with GHA, but thanks to Vibrant that has cleared up. I'm still dosing Vibrant weekly at this stage (still have some tougher turf algae) and my tests are still showing NO3 zero & PO4 0.02ppm.

I'd like to get my Nitrates up to around 3ppm. Some of my corals have lost colour but other than that seem fine. Not that I have a lot It's only a new tank (5 months old).

Tank is around 725 litres or 191 gallons total water volume including sump and allowing for rock/sand displacement (using the online calculator).

A fellow reefer gave me 100 grams of Potassium Nitrate to try. I dissolved this into 1 litre of water (that's about a quart in imperial terms).

I'm not sure how much of this I should be dosing. The guy I got the chemical from said he was dosing 2ml into his 800 lt tank, so I've been doing the same for the past week. My Nitrates still test zero however, whether I test the next day or a few hours after dosing. Using Salifert btw. However my corals have definitely coloured up some, in particular the heliofungia and a plate coral. So I'm not sure whether to just keep up with the 2ml or increase it. Does that seem enough? Also, is there a preferable time of day/night to dose Nitrate? I'm just dosing by hand.

Thanks for assistance
Michael

 

[Zack K]

My question is , how did you have GHA with no nutrients?If nitrates were truly at 0 you shouldn't have an algae issue. What Test kit are you using?

 

[Antlrman]

I continued to adjust my dosage amount in 1ml increase per day until I started to get the readings I like. I have a 220gal DT with 75 gal sump and I dose 27ml per day to hold at 5ppm

 

[Antlrman]

To be clear though, I mix 4 tablespoons of Stump Remover per 1000ml rodi water.

 

[Randy Holmes-Farley Verified Community Expert]

100 grams of potassium nitrate in 1 L of water (total volume after addition) contains 61.3 grams nitrate per liter, or 61.3 mg/mL.

So adding 1 mL (61.3 mg) to a 725 liter tank adds 61.3/725 = 0.085 mg/L nitrate.

Consequently, if you want to add, say, 2 mg/L, then you'd dose 24 mL of your stock solution.

 

[MmmmBalf]

My question is , how did you have GHA with no nutrients?If nitrates were truly at 0 you shouldn't have an algae issue. What Test kit are you using?

I'm using Salifert for Nitrate, & Red Sea Pro for Phosphate. I think most of the nutrients were originally being consumed by the algae - I've read that GHA becomes more of a problem when phosphate is up with no Nitrates, although being a new reefer I'm not sure, that's just what I've read others say. Now I think the Vibrant is keeping both low, but I want to get the Nitrate up higher than the phosphate. It'll be a continued check & adjust, as once I reduce the Vibrant to a maintenance dose, I may not need to continue dosing Nitrate. I'll wait & see.

100 grams of potassium nitrate in 1 L of water (total volume after addition) contains 61.3 grams nitrate per liter, or 61.3 mg/mL.

So adding 1 mL (61.3 mg) to a 725 liter tank adds 61.3/725 = 0.085 mg/L nitrate.

Consequently, if you want to add, say, 2 mg/L, then you'd dose 24 mL of your stock solution.

Thanks Randy, this is exactly the answer I was looking for.

 

[crzyzeldafanatic]

I'm using Salifert for Nitrate, & Red Sea Pro for Phosphate. I think most of the nutrients were originally being consumed by the algae - I've read that GHA becomes more of a problem when phosphate is up with no Nitrates, although being a new reefer I'm not sure, that's just what I've read others say. Now I think the Vibrant is keeping both low, but I want to get the Nitrate up higher than the phosphate. It'll be a continued check & adjust, as once I reduce the Vibrant to a maintenance dose, I may not need to continue dosing Nitrate. I'll wait & see.



Thanks Randy, this is exactly the answer I was looking for.

Did you ever have any luck with this. I'm having a GHA problem with phos reading .04 and nitrate dead at 0 and will not come up. I have read the same information as you in regards to algae growing with nitrates being lower than phos and i want to dose to see if it will help.