PH Swing 7.9~8.3

[patteto]

After getting Aquanotes up and running I am able to tell you that my PH swings from 7.9 (sometimes 7.85) to about 8.3 on a daily basis. The lows are at night and highs during the day. I have a Calc reactor on the tank but the CO2 is not hooked in the Aquacontroller yet. So my questions are:

1. Is this too much of a daily swing?
2. If I turn off the CO2 to the calc reactor when PH is below 8.0, I am going to loose valuable Calc dosing time (currently fighting chronically low Alk and calc a bit low)
3. Should I does Kalk at night when the CO2 is off?

Any help is appreciated. FYI the tank looks good just not getting as much growth out of my SPS as I would like. There are a few chemical issues I need to resolve (low Mag), low Alk, OK Calc.

Thanks

 

[jhammond]

I don't think its detrimental, but I would try to reduce the swing a bit. Kalk is a good idea. Check out this link for some good info.

http://www.reefkeeping.com/issues/2004-09/rhf/index.php

 

[Rick]

George said pretty much what I was going to say. The pH swing will lessen the higher your alkalinity is. The alkalinity is easier to keep up the higher your magnesium levels are (without going over safe levels). What is specific gravity? I found it easier to keep the alkalinty higher with lower specific gravity. I used to shoot for 1.026, now I try to keep it 1.024.

 

[kwl1763]

I third Rick and George. If you keep your alk on the high end it will help even out the swings. Dosing kalk might help but in my opinion is not worth it when you have the reactor. You could put your C02 solinoid on a timer that only works when the lights are on. It will only help a very very tiny amount though.

I would just raise the alk and see if that helps since the swing is not terrible.

 

[melev]

Perhaps you should test the effluent of your Calcium Reactor to see if it is producing proper levels in the first place. I recently replaced my media, and the alkalinity is much higher coming out of the effluent. It was 17 dKH and now it is more like 27 dKH, if I recall correctly. I know the other guys know what they are talking about, but it might help to review how your reactor is set up as well. How many bubbles per second are going into the reactor? What pH level do you aim for inside the reactor, using what media? And how much effuent can you collect in a minute's time? (You might collect it for 5 minutes and divide by 5 if it is hard to measure.)