PH swings since Halides added

I have a live PH meter. Since I went from t-5 to Halides, my Ph is swinging alot more. 7.8 in the morning to 8.4 at night. Halides are at 6hrs and actinics are at 11hrs. I tested my alk and it was a little on the low side at 8dkh. I checked the calculator and it said to raise slowly with baking soda. It also said it would lower ph slightly. I dont want it too low in the morning. I am afraid to buff it, cause I dont want it too high at night.....anyone??

 

Your pH is probably swinging more because there's more light available. More light = more photosynthesis = bigger swings in the O2 : CO2 ratio.

You could use one of the other kinds of alk supplements. There's a whole bunch that raise pH.

 

some PH swing is normal, if you have a fuge that is lit at night it helps reduce the swing. .6 is a fairly high swing though, its odd that it would change more with MH than with T5's, since PH drops with temperature increase. do you know what your morning/evening numbers were before?

also have you added alot of new livestock since adding MH's?


as for fixing it. the best solution is to test your Mg and then get it to 1300-1400, and after that get your calcium and alk in the inline.

 

Thanks---I know Seachem makes a product called Reefbuilder, that raises alk only. Do you think low alk is the problem? Or is my Ph ok?