Carbonate Hardness (Alkalinity) is high

[jason marshall]

Wondering if anyone could help me out. I did a test on my carbonate Hardness and it is well above 125mg. My PH is high also 8.5-8.7ish. All other parameters are perfect. I have a 55 gallon tank. Please let me know what I can do to bring this down. Also is it safe to bring this down to a reasonable level instantly? My fish all seem to be doing fine, but snails are falling off the glass.

[Bvoss]

I would just bring it down with water changes. It will drift down eventually by itself, but some water changes are always good. I am not really sure how high it is because Alk is normally measured in dkh or meg/ml. Can you tell me what your reading is in those units?

[nickb]

What test kit are you using? Is it a saltwater kit? 'mg' is a very odd unit for alkalinity. More common is meq/l, dKH or ppm.

If you meant 'mg/l' (ppm), then you can convert to dKH by dividing by 17.8. Since you want dKH in the range of 8-11, that corresponds to about 140 mg/l to 200 mg/l. THis would suggest that your alk level is actually fine.

I wouldn't change anything until you have an confirmed alkalinity measure in one of the more common units. In any event, rapid changes are nearly always bad.

[Dendro9472]

Was in the same situation, Hagen test kit, right? Your water parameters can be normal, if there is the chance to use another kit.

BTW, Hagen site has unit converter utility, under aquatic->utilities.

Eventually I bought Seachem tests (expensive), they came with calibration solution - it allows to check usability of the tests (it could be frozen during shipping to LFS). My Hagen test gave 190 mg/L, Jungle Quick Dip test strips - above 300 mg/L, and Seachem 4 meq/L, with carbonate hardness 2.5 meq/L, which is perfectly normal.

Sorry, don't know other tests, less expensive, that has calibrating solutions - I'm new to this.

If you are sure that correction of alkalinity is necessary, here is an excellent article on practical solutions of alkalinity problems http://www.advancedaquarist.com/issues/nov2002/chem.htm . Other than universal solution - large (or frequent) water changes.

Hope it helps.