pH: trust the probe or test kit?

[BonelessEvil]

I keep testing my pH and trusting the Red Sea test kit, which shows a consistent 8.0-8.4 number throughout the day. Since I like this number over that of the probe, I've assumed it was correct. Now, I replaced my Neptune systems double junction probe without of BRS, also double junction. Both of them say my tank is running low pH: 7.5-7.8.

First, which should I trust? Second, If my pH is this low, am I inhibiting coral growth? So far, nothing is dying. Also, it's been difficult to keep my alkalinity up (currently 7.1 dKh, Using 67.2 mL/day Randy's reef recipe #1 soda ash) and turned calcium dosing off as it keeps getting high (currently 490, ). Magnesium is 1400. Is it normal to dose this much alkalinity, for 88 gallon tank that doesn't have a lot of corals?

 

[EmdeReef]

I would trust a calibrated probe over a test kit. When was the last time you calibrated the probe?

 

[BonelessEvil]

I would trust a calibrated probe over a test kit. When was the last time you calibrated the probe?

2 weeks ago, so if my pH is so low (corals still happy), does that explain other numbers?

 

[JoeD_]

You will get more growth with higher pH, but the risk of chasing pH is far more greater than the reward IME. 7.8 is fine. On the flip side, the easiet, and I mean EASIEST way to increase pH safely (again IME) is dosing KALK

 

[bdare]

How long have you been dosing the soda ash? When is the last time you took your pump apart and checked the impeller?

I gave up on recipe one because no matter how slow I dosed I would end up with precipitation. Although recipie #2 will temporarily drop pH give it a shot. See if your Alk doesn't stabilize and in turn help increase your overall pH.

 

[BonelessEvil]

thanks @bdare . Yet, dosing Kalkwasser is easiest through my reservoir, but it always clogs up when I place it there.

 

[Shinte122305]

I have a tank full of corals that are gropwing and thriving at 7.7-7.85 PH day and night cycle. i wouldnt chase ph at all. Do simple things like letting a skimmer breathe air from outside or very very slowly add kalkwasser. even just 2 TBSP in 10 gallons of RO will give you a small positive boost in PH and alk/caclium

 

[BonelessEvil]

I have a tank full of corals that are gropwing and thriving at 7.7-7.85 PH day and night cycle. i wouldnt chase ph at all. Do simple things like letting a skimmer breathe air from outside or very very slowly add kalkwasser. even just 2 TBSP in 10 gallons of RO will give you a small positive boost in PH and alk/caclium

I would love to just put Kalkwasser in my reservoir, but it always gets clogged. How do I overcome that issue? Or is that always a losing solution?

 

[Randy Holmes-Farley]

A lot of folks have issues getting trustworthy pH values from controllers.