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Okayamapiper
10/06/2009, 06:39 PM
I have a denitrator whose output is a steady drip and with a pH of 8. The main tank is 8.2 and dKH over the long term is falling. Calcium is around 450, nitrates are less than 10ppm. Would the use of Kalk to raise effluent pH put enough calcium in to affect the dosage ratio for Randy's 2 part supplement? I have a 120 liter tank with a 40 liter sump dosing 20ml each of the two part supplement. I will need to dose on the order of 1 liter of kalk to neutralize the effluent.
Another option to long-term dosig would be a third reaction chamber being added to the denitrator filled with more aragonite to bring pH up to 8.2, but would an effluent of 8 be enough to dissolve aragonite to do this?

Help!!

Billybeau1
10/06/2009, 08:49 PM
argonite will not dissolve at 8.0 It actually requires a much lower pH, if I remember correctly, somewhere in the 6's.

Alkalinity will fall by design. It needs to be supplemented to keep your level in the acceptable range.

Randy Holmes-Farley
10/07/2009, 06:34 AM
I think limewater is a good option, but it need not be added to the effluent. Adding it to the tank is equally effective.

What are you claiming that 1 L is needed to accomplish?

zachtos
10/07/2009, 10:44 AM
I used to run the effluent of the sulfur denitrator (which comes out about 1dkh lower then the tank, and 0.5ph lower) to a hang off the back filter full of calcium reactor media. It helped cut those numbers in half. Aerating the sulfur effluent helps fix the ph a bit too, maybe 0.1. I run the effluent of my sulfur reactor and calcium reactor into my refugium, the macro algae likes the lower ph and co2. My growth rates doubled atleast after doing that, my tank ph didn't seem to move a lot though.

Okayamapiper
10/08/2009, 03:11 AM
Actually it is using about 1.5 liters of limewater over 24 hours to knock the effluent up to 8.2. I did not calculate it but merely plugged a doser into the effluent output and hooked a pH probe up to it and increased drip rate until I got it up to 8.2. I had to lower flow slightly as well but only slightly as I did not want the denitrator to go anaerobic.

Randy Holmes-Farley
10/08/2009, 03:51 AM
OK. Do you know the pH of the tank and/or the the incoming water to the denitrator? :)