calcium and dkh.

sbazain · Oct 3, 2015

am reading 500 cal. 11 dkh but my calc. is been going up wish is impossible i think so i went to the lfs he reads 340 cal. and 7 dkh. so i bought new testers came home and tested gave me 500 cal. and 11 dkh new testers read the same way what tester you ask api , i know their no good and all that but I've never had any problems until now and he uses api too what could be going on

Randy Holmes-Farley · Oct 3, 2015

There's obviously some sort of testing problem. We can't know which (if either) is accurate.

How old is your tank?
You might use your kit on some new salt water (what brand do you use?).

NanaReefer · Oct 3, 2015

Try another brand of kit.

Habib(Salifert) · Oct 3, 2015

Your results for both calcium and alkalinity are high by approx 50% compared to LFS. That could be a coincidence or either you or the LFS might have made an error with amount of sample. Might want to double check if you are using the correct volume of sample.

If API still uses the same type of sample vial as in the past then it is a narrow tube. For proper mixing, which is essential, the tube has to be capped and be inverted a few times after each drop of reagent.

If e.g. the LFS did not do this then a premature, albeit temporary, color change might be seen and interpreted as end of test resulting in a false low value.

sbazain · Oct 3, 2015

Ive done the test now for a few days and it keeps giving me 500 and 11 so since i dose every 6 days that's how long it takes from 460 to 420 and i keep it at 460 i checked two days ago wish was 9 days from the last dosing cause i haddent had time it was at 500 thats when i said thiers somting wrong but its been 9 days let me dose anyways so now is at 520 and 11 but not according to the lfs test and yes ive been using this test metbod now for 2 years

Randy Holmes-Farley · Oct 4, 2015

Your calcium number may be correct, or not.

You either need to test something else with a known calcium concentration, or use a different kit (preferably different brand) to try to verify it.