Water changes dropping PH levels?

[Armando_Villasenor]

I noticed that I was constantly fighting to raise the PH level in my tank. After a water change I noticed that it dropped again. I tested the pure ocean salt water I got from my local fish store and realized it was very low. Isn't the purpose for purchasing pre mixed salt water for water changes to ensure you're adding water that will improve your tanks levels???

 

[DamianOZ]

Some figures would help, and details on how your testing.

 

[cmcoker]

Agreed, what are you considering low, how are you testing it, you generally don't want to chase pH. Also, What is the specific gravity and alkalinity, calcium, and magnesium.

 

[Sabellafella]

aerate the freshly made saltwater untill the ph stops rising

 

[Armando_Villasenor]

60 gal fish and reef tank. 6 fish
Test using API test kit
Salinity 1.024 - 1.025
Phosphates 0-.25
NO 0
KH 7
Ca 480
I get the PH up to 8.2 using a PH buffer.
I noticed the PH dropping after a 10% weekly change so I tested the new water and it was 7.8

 

[TaylorPilot]

Do you have a skimmer? The most typical and easily fixed issue for low PH is a gas exchange issue. Skimmers work great at removing CO2 from the tank. Curious to see what would happen if you opened up the doors to your stand for a day or so, then tested. Do you dose Kalk for an additive? That naturally raises PH.

 

[TaylorPilot]

OH, and welcome to R2R!!!!!

 

[Armando_Villasenor]

I have the Redsea 250 so all equipment is built into the back of the tank including skimmer. Yes I do dose for Kalk.

 

[Armando_Villasenor]

Thanks everyone

 

[Randy Holmes-Farley Verified Community Expert]

Just to clarify, pH is determined ONLY by the alkalinity and the CO2 level in the water.

The CO2 level is usually primarily determined by the CO2 level in your home air, assuming you have adequate aeration.

The pH may drop after a water change (or rise), but those effects will be short termed until the tank reaches a newe stable state with respect tot he air.

Finally, buffers are not the best way to deal with low pH, if that is a concern.

At pH 8.2, I would not worry about it, but this has more:

pH And The Reef Aquarium
http://www.reefedition.com/ph-and-the-reef-aquarium/