low calcium levels

[purplepolypeater]

try a different test kit calcium test kits can oxidize take a saltwater sample to the lfs. that is a lot of calcium lost to virtually no coral was that after your weekly water change. is it a new bucket.

[sphelps]

Check you magnesium, when it's low it's very hard to maintain calcium levels. Also IO salt will have low calcium and alkalinity when mixed with RO water, it's made to work best with plain old tap water. In addition when only mixing up small amounts of salt you'll get different results every time, one time you might scoop up a lot of calcium, other times hardly any. Ideally you want to mix a full bag or pail at once but obviously that's not always practical. Any two part additive will work fine, they're all pretty much the same, you can also make your own if you're interested.