Kalkwasser in FO tank?

[ladyshark]

I have been perusing reefcentral for info on PH (and the need to raise it). There are some interesting thoughts about "this time of year" and use of A/C which prohibits the simple opening the widow approach.

My 125 FO seems fine, PH-wise, so long as I keep the covers up during the day with my koralia pointing toward the surface for rolling the water at the surface. However, my 75 is pretty much open top, plenty of surface agitation and ph is 7.8 during the day. Could be due to the house being closed up, not sure.

At any rate, I came upon the idea of Kalkwasser drips, of course, and found this idea used by a member:

"I really find using buffer keeps ph locked to 8.2 in my tank. ... I use a teaspoon of buffer in 1 cup water and mix 'till clear and dump it into the sump return flow. Check your KH once a day 'till it is at a level you want. Then about once a week after."

Does anyone see a problem with dumping Kalk water into a sump like that for a FO tank (in terms of its effect on the fish)?

 

[sacremon]

My main concern would be that you would be limited in how long you could dose the tank. You don't want Ca to get too high, and unless you have a lot of coraline algae in the FOWLR tank, there isn't much to take Ca out of solution.

 

[jda]

How are you testing the PH? Also, what is your alk?

Your daytime PH should be higher than 7.8 (tested with a meter) if the alk is in a decent range... but there is always a slight possiblity that it might not be.

If you are using a color charted test kit, then I would question the test kit before I would do anytying to the tank.

Kalk is a fine way to solve a lot of problems, but there are also risks if too much gets added at a time.

If you do a kalk slurry (the method that you are suggesting), it can raise the PH VERY quickly. I would need to know how large of a tank your quote is from. A teaspoon of kalk added all at once in a 75G tank could take the PH well over 9.0 or 10 in about 10 seconds. This could kill your fish and even maybe some of your bacteria. If you do want to try this method, then a digital PH meter is a must... and start out with about 1/16th of a teaspoon and pour the mixture in very slowly and allow a few minutes for the PH to adjust. You will get the hang of it by watching the meter. However, this method will not keep your PH up for long - the tank will quickly replace the driven-off CO2 in the water with CO2 from the air and the PH will lower again.

Test your alk with a good kit (like salifert or equivalent) and then give us a morning (before the lights come on) and an evening (before the lights go out) PH readings with a calibrated meter or pen.

 

[ladyshark]

Will do--mine is a color test, but I will get a calibrated and pass on results.

In the mean time, no way am I risking the kalk slurry--it sounded overly simple. I think the guy I quoted had 220 tank. The tank I am thinking about is the 75, so your points are well taken.

I have learned to think and ask first before doing......

Thanks!!