Kalk question

[Duberz]

My alk has gone from 135,133,131 in the last three days. I'm starting kalk in my ato. What amount of kalk/gal will keep my alk steady? I mixed up 2 tsp/gal but I figured I'd ask before starting. Also I'm going to raise it up 1dkh before I start the kalk.

 

[miamiangler]

2TSP / gal works for me My dKH Is between 8-9 when using it in ATO topoff

 

[menglish]

I first started with 1 tsp/g but that was not enough to maintain my levels where i wanted it. I am now dosing 2 tsp/g. I am still testing. Keep an eye on your ph levels. I fear this will not work for me so i already purchased BRS 2 part kit and will likely start that up next week

 

[sawdonkey]

My alk has gone from 135,133,131 in the last three days. I'm starting kalk in my ato. What amount of kalk/gal will keep my alk steady? I mixed up 2 tsp/gal but I figured I'd ask before starting. Also I'm going to raise it up 1dkh before I start the kalk.

I assume you're talking ppm? That's a pretty tight range if you ask me.

 

[reefndude]

I personally use 2 1/2 tbsp per 5g of water. I'd recommend starting low and test to see what works for your tank.

 

[Randy Holmes-Farley Verified Community Expert]

Yes, that range is too tight to make any sort of accurate determination of the demand. No home kit could reproducibly distinguish those levels.
The demand is also VERY low.
Let it go longer, and start now with 1 level teaspoon per 10 gallons of fresh water in the ATO and see what that does to alk over a week or two.

You can use this calculator to see the effects of saturated limewater (2 teaspoons per gallon), but adding 1.25% of the tank volume (1.25 gallons in a 100 gallon tank) will boost alkalinity by 1.4 dKH (0.5 meq/L; 25 ppm calcium carbonate equivalents), so it appears that you need far, far less in your ATO.

Reef Chemistry Calculator

That said, the higher the alk and the higher the pH, the higher the demand for alkalinity. So measurements made when not dosing are, at best, estimates of what will happen if you dose.