low alkalinity and high ph

[boosst]

i noticed my PH today is up to 8.66. it is usually about 8.2-8.4. so i ran some tests and my alkalinity is low(2.5 meq/l) but my calcium is in check at 400. any ideas as to what is going on? i usually use c-balance once a week with water changes but that is all i put in it. what can o do to balance this out? thanks

[SDguy]

Confirm your pH with another test. I would use the reef chemistry calculator to figure out how much of whatever product you choose, you need to get you alk up.

[boosst]

i used a sea chem manual tester and it isn't too accurate but shows a ph of about 8.4-8.5...my aqua controller jr shows a digital ph of 8.66.

[SDguy]

Have you cleaned and calibrated the probe? How old is the probe?

[thrillreefer]

how do the inhabitants look? are the corals' polyps retracted?

[drummereef]

Yeah, I would make sure the probe is properly calibrated and re-test. The alkalinity is low, but probably not detrimental. I prefer to keep mine around 3.5-4meq/L. Using your C-balance on a daily, instead of weekly, basis will help with large fluxuations in alk/ca.

Calculator to help with dosing.

Reef chemicals calculator
http://home.comcast.net/~jdieck1/chem_calc3.html

[boosst]

the probe is only about 3 month old. everything in the tank looks and acts fine. i do a weekly water change so i will watch it close until the next one and maybe that will help it out. i will also try using the c-balance more regularly. thanks

[hankthetank]

Low alkalinity can produce high pH just as easily as it can produce a low pH.If alot of photosynthesis is occurring in a system with low alk the ph can easily get that high.Check your pH
right before your lights come on and it will probably be in the mid to high 7's.

[Frick-n-Frags]

when your buffer is weak, the pH goes all over the map.

maybe a mid-week baking soda supplement would help [raises alk, moderates pH toward 8.1]
use the calculators to figure how much you want to raise the alk, but probably don't go much more than .5meq per dosing

[boosst]

ok. i added another dose of the c-balance and my ph is still rising. now it is at 8.71. it usually drops to the high 7's before the lights come on and climbs to 8.3ish but the last few days it has just kept climbing. this morning before the lights came on it was still 8.34. will adding baking soda mess with anything in the tank? discolor water or damage fish or invertebrates?

[boosst]

i used the calculator and am now adding baking soda. it says not to let the ph drop more than 0.20 at a time. can i just keep adding my designated amount until this happens or do i need to dose over several hours? thanks

[boosst]

alright...i added the amount of baking soda that it told me too over a couple hours. my ph today is now 8.75 and rising everyday...what else can i do?

[boosst]

i also started dosing the tank again with baking soda. it goes from 8.75 down to about 8.59 with a small dose and in about 45 seconds starts climbing back up slowly to 8.7X. should it stay down with a baking soda dose or is this normal?