Kalk Dosing - Unexpected Results

[jjencek]

I have always had low Ph measured with Apex probe. The Ph would range from 7.45 to 8.0 being the lowest in the morning after lights out and on a good day reaching 7.9 or 8.0 by the end of the light period.

I wanted to increase the Ph so I started Kalk dosing using my ATO (1 tsp per gallon of ATO water). For the last week of dosing I see no measurable difference in Ph. The Kh and Ca has gone up and I had to turn down my 2-part dosing of these two.

Here are my other parameters:

65 gal tank - 15 months old - RedSea Max 250

Carb dosing using vinegar (20 ml per day for 60 gal tank) due to excess of red hair algae

I open windows every day for fresh air, hood opened, stock protein skimmer

Salinity 1.025
Alkalinity 8.5 (auto dosing)
Calcium 470 (auto dosing)
Magnesium 1250 (auto dosing)
Nitrate 0.02
Phosphate close to Zero
Temp 76

Why is my Ph refusing to move?

 

[RobZilla04]

Why do you want to increase the pH? I'm certain in doing so you're gonna create more problems than it's worth.

pH is mostly tied to CO2 content in the room the tank is in. If you increase after surface agitation in both the DT and sump, you should see the pH rise.

And again chasing a pH value is pointless. If it's in the acceptable range leave it alone.

 

[josephxsxn]

Second the co2 problem, that was the sole cause of low pH in my tank. After performing an aeration test with tank water both indoors and outdoors I found I have insufficient gas exchange going on. I ran a airpump out my windows with two stones in my sump and my PH has never dropped below 8.0 again even during the nonphoto period.

Take a glass of tank water and put it outside with an air bubbler running for 30 minutes and test the PH, if it increased you have a gas exchange issue. Then repeat the same test with another glass of reef water indoors. If the indoor test does not change you probably have a co2 issue in the house, if it changes and almost matches the outdoor test you should increase your surface agitation to promote better gas exchange.

 

[Daddi0]

While the Kalk raises PH, the bacteria from the vinegar dosing are lowering your PH

 

[mcgyvr]

results exactly as expected...
stop looking at PH and your problems go away

 

[bertoni]

I am suspicious of the 7.45 pH reading. That's very low, although possible. I'd check the skimmer to see that it's aerating properly, and look at the water surfaces to make sure that they are clean. How are you measuring pH?

 

[jjencek]

Ok, I have heard it now from 5 people - don't chase the Ph. I am ready to listen.

Now here comes the "oops" part of my reports ....

I calibrated the probe again - and the Ph is where it should be 7.9-8.2. So here you were also right.

I was married for 20 years - I should know I am never right. :facepalm:

 

[RobZilla04]

Ok, I have heard it now from 5 people - don't chase the Ph. I am ready to listen.

Now here comes the "oops" part of my reports ....

I calibrated the probe again - and the Ph is where it should be 7.9-8.2. So here you were also right.

I was married for 20 years - I should know I am never right. :facepalm:

Don't beat yourself up too bad, it's natural to think straight to the worst when something is outta whack. Calibration or ensuring test accuracy somehow gets forgotten about.