View Full Version : Stable Alk, low ph

07/13/2017, 09:19 AM
So my tank Alk stays around 9.2-8.6 thanks to Kalk, however my pH is 7.5-7.6 off my apex. Should I even worry about the ph if the Alk is stable?

07/13/2017, 01:53 PM
I suspect that the pH reading is a bit off. It'd be very rare (although not unknown) to have pH that low. Does the tank have a skimmer? If so, I might sure that it's tuned to make fine bubbles, and check for surface films on the water. Otherwise, I'd ignore the pH as long as the animals are doing well.

07/13/2017, 05:15 PM
As Bertoni said your PH #s sound off, try calibrating your apex probe then see where it lands.

If your PH is actually that low it's probably a CO2 problem. What I'd do (and did in my case) was let the ALK drop a little, keep using kalk and add a small air pump and 2 airstones in sump return section. (near return pump) Mine went from 7.8 - 8.1 swing to 8.13 to 8.26 swing and it's steady as a rock

07/13/2017, 05:28 PM
The ph is low. Calibrate the PH probe, for sure. Do you use Calcium reactor or are you dosing? Ca reactors cause CO2 in tank to elevate which lowers the PH. Do you have a hood? Open the doors and see whether the PH increases. You need the gas air exchange to be sufficient by having a recirc pump pointed upward toward the surface to break surface tension. Using fans in the canopy may help. Also, your skimmer should increase PH too.
If using a CA RX, use the xxcourse CA Carbonate rocks. The PH seems to quite high and not effected by CO2 from reactor.

See how that works. But, your PH is low which makes it harder for the coral to calcify and create skeleton.

07/13/2017, 08:50 PM
Thanks everyone. I will recalibrate the apex. Yeah most things are doing well, have a couple sps, zoas,scolys, tons of hammers and everyone is thriving except I did have a loss of a frogspawn for no reason at all this week. I would have thought my SPS would have gone before anything although I doubt it was a PH issue.