Dosing Nitrate

[Randyp79]

I'm trying to figure out where to begin with dosing KNO3. My system is about 4 years old and I have been carbon dosing vinegar for the past 2 years. I achieved undetectable nitrates and phosphates for a while, but now my phosphates are running around .02 (Hanna ULR) while my nitrate has remained undetectable. I have tried feeding more but that has just led to higher phosphates. I am considering KNO3 dosing because my acros are growing slow and have pale color.

I have prepared my stock solution of KNO3 (5ml = 1ppm NO3 in 180 gallon) but I am unsure how much I want to dose per day to start with. I am thinking if just starting with 1ppm per day. Should I start with more or less?

 

[Martin Kuhn]

What about
- starting with 1ppm per day
- measuring after 24 hrs what your tank consumed
- decide on how the next dose(s) should be then

Continue on day 2..n according the nitrate level you want to achieve. E.g. 2 ppm as target value

 

[Randyp79]

I created a custom solution where 5ml=1ppm in my 180 gallons of total water volume. Before dosing, my NO3 was undetectable and my PO4 was 0.02 ppm (an imbalance I attribute to my carbon dosing with vinegar). I dosed 10ml or 2 ppm NO3 and tested a couple of hours later and had a reading between 1 and 2 ppm, which is right where I want to be.

After 48 hours of 1-2 ppm NO3 I have noticed significantly better colors in my corals. I have a WWC Space jam Stylo that was pale and looked bleached that is now a deep dark purple.

I put the KNO3 on my GHL doser and it is dosing .5 ppm per day. Hopefully, this will keep me right around 1-2 ppm overall.

The only negative I have noticed, if you want to call it that, is that the vinegar plus the NO3 has bottomed out my PO4. Phosphate was undetectable this morning but I was able to register .01 ppm after a heavy feeding this morning with PE Mysis. I went ahead and took my GFO offline in hopes that it would help increase phosphate a little. Hopefully NO3 dosing will allow me to eliminate GFO from the equation since KNO3 is WAY cheaper than GFO.

I guess I'll just have to feed more to keep my phosphate up, so my fish should be happy.

 

[Crimsonvice]

Can you explain how you made your custom KNO3 solution? I am having issues with low nitrates also.

 

[chipmunkofdoom2]

The only negative I have noticed, if you want to call it that, is that the vinegar plus the NO3 has bottomed out my PO4. Phosphate was undetectable this morning but I was able to register .01 ppm after a heavy feeding this morning with PE Mysis. I went ahead and took my GFO offline in hopes that it would help increase phosphate a little. Hopefully NO3 dosing will allow me to eliminate GFO from the equation since KNO3 is WAY cheaper than GFO.

A bit of an old thread and old post, but why are you dosing nitrates while also dosing organic carbon? There's no hard and fast rule that you can't do both at the same time, but you really should have a very good reason for doing so. If your nitrates are so low that you have to dose them, I personally wouldn't be dosing organic carbon.