PH Super High

[Bmartinez76]

My tank has always struggled with PH, I averaged between 7.87-7.98 is, but hardly ever above 8. Recently we started getting colder weather than normal here in Florida and my PH has skyrocketed to 8.12. I tested last night and my ALK was at 8.7, Cal 450, Mag 1300. I am dosing 60ml of ALK using a APEX DOS (through the day on alternating schedule of CAL) and Cal i dose 42ML. I've been dosing Kalk as well (30ml) to maintain parameters. My tank is just about 1 year old now. Should I be concerned about the PH swing? I don't see anything fainting or convulsing, but I'm sort of a rookie and want to make sure I'm taking the appropriate steps to maintain my reef tank.

One other thing to note is that previously I was not able to grow cheato in my refuguim and as of late it started to grow nicely.

This is my Kalk programming in case it helps.
Fallback OFF
OSC 040:00/001:08/018:52 Then ON
If pH > 8.35 Then OFF
If KalkSw CLOSED Then OFF

Any input advice would be appreciated.

 

[Brew12]

8.12 is not high at all.
It is possible that the chaeto growth is pulling CO2 out of the tank and causing pH to go up.

 

[redfishbluefish]

Your pH is just fine. What is causing the change (assuming no testing error) is CO2 in the water. What is odd is that pH usually drops in winter with the house closed up and a heater running. But again, no issue with that pH.

 

[Bmartinez76]

Great thanks for confirming. The house is currently at around 69-72 with the cold air. I'm on forced heat with my house generally just using the cooling all day (I didn't turn on the heater during the day, only at night for the kids). As a technical person my first thought is what has changed in my setup and going from there. I added 2 mangroves to my refugium and that's when I noticed my cheato has grown substantially and assumed that might have something to do with it.

 

[moray69]

Check your ph probe calibration. Just in case....

 

[Bmartinez76]

Check your ph probe calibration. Just in case....

Planning on that, but didn't have the solutions on hand. Will be getting some later this week.

 

[Specfishin]

Fwiw, I'm in Florida and my ph has been laying low from 7.4-8 until the cold hit. Now its sitting steady and slowly rising anywhere from 8.3-8.5.
I was just getting ready to run a fresh air intake line to my skimmer.my ph was running low with the skimmer off for a few days at a time. Now I leave it on except feeding

 

[Specfishin]

Oh I also swapped my fuge lighting from 24/7 to opposite display. I really think between florida homes being couped up with ac on , we dont get a very good air exchange from outdoors

 

[arman]

Hey guys what are yr ideas about the results of much higher ph on reefs and fishes?for example ph around 8.5 to9

 

[redfishbluefish]

Hey guys what are yr ideas about the results of much higher ph on reefs and fishes?for example ph around 8.5 to9

That's called testing error or someone dumping something nasty into your tank (a very strong base). Otherwise, it can't happen.

 

[arman]

That's called testing error or someone dumping something nasty into your tank (a very strong base). Otherwise, it can't happen.

Im dosing kalkwasser to my tank very carefully, i wanted to know if i dose it with a dosing system in my tank in different times with 40ml every time(24 times a day) could raise my ph up to 8.5?
I use two teaspoons in 1 gallon to make the solution.

 

[Brew12]

Im dosing kalkwasser to my tank very carefully, i wanted to know if i dose it with a dosing system in my tank in different times with 40ml every time(24 times a day) could raise my ph up to 8.5?
I use two teaspoons in 1 gallon to make the solution.

I have to ask, why do you want your pH that high?

Once you get above 8.4 you will start getting some precipitation of Calc and Alk in the form of Calcium Carbonate. You will need to work very hard to keep those parameters where you want them. It will also likely require a CO2 filter along with the Kalk to keep enough CO2 out of your system.

 

[redfishbluefish]

With saturated kalk you could drive your pH above 8.5....but you don't want that....you're either adding too much or too fast. And @Brew12 ,without looking up the chemistry, I believe you want and need the CO2 in the tank so that the hydroxide can react with the carbon dioxide to form carbonate. But I agree with Brew that you're now going to start getting precipitation of calcium carbonate and other goodies. I'm not a kalk user but believe Randy is and I'm sure he can clarify the chemistry and pH issue..... @Randy Holmes-Farley

 

[Brew12]

With saturated kalk you could drive your pH above 8.5....but you don't want that....you're either adding too much or too fast. And @Brew12 ,without looking up the chemistry, I believe you want and need the CO2 in the tank so that the hydroxide can react with the carbon dioxide to form carbonate. But I agree with Brew that you're now going to start getting precipitation of calcium carbonate and other goodies. I'm not a kalk user but believe Randy is and I'm sure he can clarify the chemistry and pH issue..... @Randy Holmes-Farley

The CO2 in the tank combines with the water to form Carbonic acid which drives down pH.
CO2+H2O = H2CO3

The Kalk works by converting some carbonic acid into bicarbonate.

pH is an equilibrium reaction in a tank between carbonic acid, bicarbonate, and carbonate.

H2CO3 <-> H + HCO3 <-> 2H + CO3

If you add CO2, it shifts the equation to the left and lowers pH. When you add Kalk {Ca(OH)2} it dissociates into CA + 2OH. The OH reacts with the carbonic acid (H2CO3) to become bicarbonate which shifts the equation to the right and raises pH. OH + H2CO3 -> 2HCO3

 

[Brew12]

My inner geek came out.. didn't it?

 

[redfishbluefish]

Here's a good read from Randy:

What Your Grandmother Never Told You About Lime

This should clear things up.

 

[Brew12]

Here's a good read from Randy:

What Your Grandmother Never Told You About Lime

This should clear things up.

That is one of my favorite ones. Fascinating on how you can use Kalk to raise pH but you can also use it in combination with vinegar to drop pH.

 

[G8trBait16]

I have a DIY CO2 scrubber connected to my skimmer. I am getting 8.25 at night and 8.5 during the day. I live in Central FL, the CO2 scrubber has helped out tremendously especially during the summer months when you couldn't open the windows/doors. Recently I have been keeping the windows and sliding doors open in the back when I get home from work, until I go to work the next day.

 

[arman]

I have to ask, why do you want your pH that high?

Once you get above 8.4 you will start getting some precipitation of Calc and Alk in the form of Calcium Carbonate. You will need to work very hard to keep those parameters where you want them. It will also likely require a CO2 filter along with the Kalk to keep enough CO2 out of your system.

I dont want to raise it that high. I meant that if it could be that high by the dosing program i mentioned.

 

[Brew12]

I dont want to raise it that high. I meant that if it could be that high by the dosing program i mentioned.

Ah, ok. Yes, it is possible. It is also unlikely.