Low pH

[sanchezkk]

I tested my reef tank ph today and I found it to read 7.8. Please tell me what could be the cause and possibly how to raise it.

 

[Ingy]

What's your alkalinity at? Normally the Alk buffer you add will increase pH to a target level around 8.3.

 

[sanchezkk]

I'm not testing for alk yet. Should I? My tank is over a year old.

 

[jeffaquarius]

Topping off with low PH and with slow water surface movement will drop it down.

 

[Ingy]

I'm not testing for alk yet. Should I? My tank is over a year old.

If you don't have corals it's not critical to test for it. But I would every once in a while as alkalinity dictates pH stability.

 

[sanchezkk]

Topping off with low PH and with slow water surface movement will drop it down.

Please elaborate. Thanks

 

[Ingy]

What he's saying is that poor oxygen exchange can lower pH. Having a closed lid on your tank, even a glass one will cause CO2 buildup and that lowers pH. Plants, even algae will produce CO2 at night when the lights are off which is why tanks tend to have lower pH in the am. Make sure you have good surface agitation for aeration.
Topping off with water with a pH near 7 will cause pH to drop, BUT the flip side to that coin is the water that evaporates will be free of carbonates causing pH to rise until the top off is added. Those two things should balance out in the end and shouldn't be an issue.

 

[Gregcoyote]

Look into the alkalinity/calcium/magnesium balancing act that goes on in saltwater. You are seeking ph stability, not necessarily one particular number.

 

[Phranque]

Look into the alkalinity/calcium/magnesium balancing act that goes on in saltwater. You are seeking ph stability, not necessarily one particular number.

+1 And 7.8 isn't really low......

I couldn't even tell you what my pH is.... I probably haven't checked it in 6 to 8 months. My calc, alk, & mag are all good & my tank is happy and healthy.... Too many people get hung up on pH.

As I run off to grab my test kit out of curiousity.......