How much saturated Kalkwasser can be dosed at a time without PH spike?

[b4tn]

How can I calculate PH increases with saturated Kalkwasser? I am trying to figure out if I can add 30ml an hour safely to 50 gallons of actual water volume. My dosing pump will only dose 24 times in a 24 hour period.

 

[dragon99]

30ml at time in 50gal would be a fairly significant increase. I haven't seen a calculator though that gives a number.

 

[b4tn]

30ml at time in 50gal would be a fairly significant increase. I haven't seen a calculator though that gives a number.

That seemed like a lot to me also. Its 50 gallons of actual water volume though. The tank is a 75g and the sump is a 40 breeder.

 

[Randy Holmes-Farley]

That plan is fine.

Adding 0.5 meq/L (1.4 dKH) of alk this way instantly boosts pH by about 0.6-0.7 pH units (less at high tank alk, more at low tank alk).

So adding 0.1 dKH at a pop is likely fine.

Adding 30 mL to 50 gallons is only about 0.02 dKH.

 

[b4tn]

Thanks, I just finished setting it up. It took me a full week of dosing and testing to get my water up from 5.6 dkh and 380 ppm. My consumption is between .4 and .5 dkh every 24 hours. I got my water balanced out at 8.3 dkh and 425 ppm. My first dose of 30ml of kalkwasser is set to go in about an hour.

 

[b4tn]

Took forever with tweaking amounts but I finally got it right. My calculations where way off which I don’t get. When I was on the lower end of the alkalinity spectrum I was using between .3-.5 dkh per day. All said and done I am dosing 1700 ml per 24 hour period which is closer to 1 dkh per day. Does alkalinity use increase as the level goes up? Also is it safe to say that it doesn’t mater if I add 2 tsp or 4 tsp of kalk to 1 gallon.... it’s saturated so it’s concentration is the same? I ask because my main container is 1 gallon and my pre mix containers are 3 liters. I have just been adding 2 tsp regardless If it’s 3.7 liter container or 3 liter container.

 

[chipmunkofdoom2]

Does alkalinity use increase as the level goes up?

In general, yes. As carbonate alkalinity becomes more available, it's easier for corals and calcifying organisms to use it. Additionally, when you dose limewater, you're also raising the pH, which may also increase alkalinity and calcium use.

Regarding how much calcium hydroxide you can add to a gallon, the max saturation is about 2 tsp per gallon. If you add any more than that, it won't dissolve, it will just settle to the bottom and you'll dump it out next time you clean out your reservoir. Basically, you're wasting it. I personally always add a little bit more than 2 tsp per gallon, but by that I mean I use generous teaspoons. I don't add any more than 2 generous tsp per gallon.