pH Questions

[Ereefic]

I'm in the process of setting up my calcium reactor on a 130 gal. SPS system. I'm hoping to get away from mixing kalk in a 2.5 gal. container anymore (fingers crossed).

So I got the reactor ready to go and calibrated the new pH controller and the tank pH is 8.0 after lights have been on for a couple of hours.

Alk. was at 8.6 dkh but I added some buffer to bring it up to 10 dkh, which is where I plan to run it. pH jumped a little when I added it but settled back at 8.0

I'm thinking of running some airline out the window to draw in outside air into my beckett skimmer. Sound good? Any other advice? I've read your articles but don't comprehend it well.

[Randy Holmes-Farley]

I wouldn't keep bumping with buffer as that will depress calcium over time, but otherwise that sounds good.

The fresh air may or may not give you the pH boost that you want. Opening windows helps a lot (but not in January in Wisconsin :D ). Airlines to the tank are usually less effective because the top of the tank is stilll in the high CO2 air. Limewater would likely give a bigger effect.

This article may help:

Low pH: Causes and Cures
http://reefkeeping.com/issues/2004-09/rhf/index.htm

[Ereefic]

I used superbuffer dkh and brought my Alk. back up to about 10.5dkh and the pH is now at 8.1

Would a kalk slurry work (say, just after lights out) or would a drip still be necessary?

[Ereefic]

I have an auto top off that holds 10 gal. and adds about 3/4 of a gallon at a time about 3-4 times a day. Could I add a small amount of Kalk to that 10 gal. of top off and it would be enough to keep pH up yet not raise my Alk. and Cal. levels?

I so don't want to mess with a kalk drip ever again. :)

[Randy Holmes-Farley]

Would a kalk slurry work (say, just after lights out) or would a drip still be necessary?

Some folks use lime slurries, but I prefer settled limewater. If you use a slurry, use it just before lights on, IMO.

In the January reefkeeping.com I have a long article on limewater that discusses dosing. Here are some comments about using the slurry method:

"5. Delivering a small amount of solid lime slurried (dispersed) in a small amount of water. Adding one level teaspoon of solid lime (Ca(OH)2) slurried in a cup of water to 40 gallons of aquarium water all at once raises the pH by 0.6 to 0.7 pH units. That is clearly too much. Adding a smaller portion all at once can, however, be acceptable. Adding, for example, 1/4 teaspoon to 40 gallons will raise the pH by only 0.1 to 0.2 pH units. Unless the pH is high (>8.4) before the addition, that amount is likely acceptable. The other concern with all at once dosing is that the local pH in the area of the addition will rise considerably higher than the values above. Moreover, dosing a slurry raises the added concern that the solids must dissolve before encountering organisms that may take them up and be harmed. So it is best to dose such materials to a sump, and watch that they completely dissolve before reaching the main aquarium or a refugium. In many aquaria, such restrictions make all–at-once dosing of a slurry prohibitively risky to living organisms."

[Randy Holmes-Farley]

I have an auto top off that holds 10 gal. and adds about 3/4 of a gallon at a time about 3-4 times a day.

That 3/4 gallon of saturated limewater added to a 55 gallon sump adds about 0.5 meq/L of alkalinity, and so will raise pH in the sump by more than 0.5 pH units.

You could put a little lime into that top off water, and have some pH raising effect. Say, 1/4 teaspoon per fresh water gallon to start. :)

[Ereefic]

As a little test last night, I added 1/4 tsp. of kalk to 2 gal. of water and added that to my top off resivour which had 3 gallons or so still in there, so a total of 5 gal. of top off water and 1/4 tsp. of kalk. The water was clear. The top off fired and topped off the tank with approx. 3/4 of a gallon and the pH rise in the tank by .1

Then the top off water became kinda cloudy and still is at this point. If you do the math on that, does it sound right? Is this a possible way to help keep my pH up? Concerns?

[Ereefic]

Guess I should add that the sump area (return area) where I add the top off water is about 9.5 gal. if that will make any difference.

[Randy Holmes-Farley]

Then the top off water became kinda cloudy and still is at this point. If you do the math on that, does it sound right? Is this a possible way to help keep my pH up? Concerns?

The top off water is fresh water, and was initially clear but is now cloudy? If that's it, then it probably came as some CO2 entered it from the air and produced some calcium carbonate particulates in the limewater. That's not a big problem, but I'd keep the top off covered to limit it.

[Ereefic]

Yep, that's it. The top off is mostly covered (10 gal. tank) except for the small area where the PVC exits the top of the top off tank and goes to the sump.

[Randy Holmes-Farley]

Then I wouldn't worry much about the cloudiness. I discuss those processes in this article:

The Degradation of Limewater (Kalkwasser) in Air
http://reefkeeping.com/issues/2003-05/rhf/feature/index.htm