Alkalinity decrease after adding ammonia/ urea!?

[Dan Reef]

I tested more than once: after dosing a combination of urea/ ammonia to increase NO3 to just 1ppm, the alkalinity consumption reduce by 20%!

If I stop dosing, it increases again but NO3 go to undetectable levels.

What could possibly be the cause ?

 

[Randy Holmes-Farley Verified Community Expert]

What kind of ammonia?

Consumption of nitrate adds alkalinity. 2.3 dKH for each 50 ppm consumed.

 

[Dan Reef]

Ammonium bicarbonate

I added 8g of ammonium bicarbonate and 14g of urea in 1 liter and dose 4.5ml / day in 300 liters tank

 

[Randy Holmes-Farley Verified Community Expert]

Ammonium bicarbonate

I added 8g of ammonium bicarbonate and 14g of urea in 1 liter and dose 4.5ml / day in 300 liters tank

How long did the dosing go on to see how much alk demand decline?

 

[Dan Reef]

I can notice in a week.

I was dosing 60ml of triton/ day and I had to reduce to 50ml/ day. I’m not sure how much precisely that is in alk/ day

 

[Randy Holmes-Farley Verified Community Expert]

Not sure why you observed a drop in alk demand. I consider urea dosing experimental.

 

[Dan Reef]

I also have a friend that noticed decreased consumption after adding ammonium bicarbonate

Not sure why too…

Thanks !

 

[helmsreef]

I currently dose ammonium chloride at 20ml a day with no loss in consumption. If anything it has increased my alk consumption.

 

[Randy Holmes-Farley Verified Community Expert]

I currently dose ammonium chloride at 20ml a day with no loss in consumption. If anything it has increased my alk consumption.

FWIW, ammonium chloride itself depletes alk when added and consumed. Thus, at least some increased alk demand is expected.