low pH and normal dKh??

[birdgojeromy]

I have a question regarding a 4 month old tank that has been doing quite well until the last couple of weeks. Although the fish seem to be happy, the xenia I have had that has been growing like a weed the last couple of weeks has started to look unhappy. I had previously been using a test kit to monitor pH and alkalinity but finally acquired an electronic pH meter. Anyway; the results today came back as:
pH=8.01 (calibrated today)
Alkalinity: 3.54 (9.9 dKH)-Salifert
NH4/Nitrite/Nitrate/PO4=undetectable
Temp (mid-day) 80.7F SG=1.026 (refractometer)

Is it possible to have a low pH with what appears to be adequate buffering in the system and what would be the best way to correct it? I am presuming since that is the only 'abnormal' parameter that it is why the xenia look "unhappy".

Thanks!

 

[VINH_XUAN]

My tank is pretty much same as yours : age, parameter...and same

scenario too.

The Naturereef kit read 4.75 dKH
Digital pH read 7.9-8.0
Calcium 650-700

Been this way for 1 week, everybody happy except the flower cup

coral.

I've been doing 25% each week, hope can bring down the alk.

Thank you for others suggestions

 

[atkinsg]

birdgo,

Excess CO2 dissolved in the water can cause low pH. You can test this by putting some of your tank water in a container, and putting the water outside, preferably with some aeration. After a couple of hours, test the pH to see if it has gone up. If it has, your problem is CO2

 

[Fast Fred]

a pH of 8.01 is not too bad, but do check for the CO2 as stated above.

When checking pH, are you doing it after the lights have been on for at least a few hours? Try checking it at the end of your light cycle and see what it is.

 

[mg426]

i think the advice given is very good. Co2 will drive down your ph. this is an easy thing to find out as stated above. I am pretty sure that xenia start acting unhappy when the ph falls below 8.2 best of luck. Just a thought are you running a skimmer.? they do help with aeration

 

[birdgojeromy]

Thanks for the advice; I will try to increase the aeration and see if that helps. I am running a Superskimmer and have a 20 gallon sump that was originally constructed to be a wet-dry (with bioballs that I took out) and now is set up with a refugium. It has a pretty high rate of water flow but I honestly do not remember the pump size on the return (it came with the sump).