When to add conditioner during Weekly water changes

Why else would the manufacturer write “ can be used safely “ and use a half dose.?
It is in the manufacturers interest for you to finish the bottle as soon as possible.

 

I looked into chemical deoxygenation of water a while ago and the dose to remove 5 mg/L of oxygen from 10 gal is between 1.5 (sodium sulfite) and 2.3 grams (sodium metabisulfite). I highly doubt Safe is a significantly more powerful reducing agent than either of those.

A catalyst (typically copper or cobalt) appears to be necessary.

A normal dose of Prime for 10 gal is the same as 235 mg of Safe.

A 5X dose of Prime would get you halfway there.

I'd say dechlorinators (at least Prime and Safe) probably won't dangerously lower dissolved oxygen levels even if overdosed.

I'd reserve final judgment for when I actually get around to testing this though.

I think it was irresponsible for Cory to make a video saying dechlorinators are dangerous without actually testing. He has a dissolved oxygen meter (albeit a junky one) too.