I have a 29 gallon and change 50% once a week. I've been adding a few hand fulls of crushed coral substrate to the bin I use to mix the salt in because I was worried the ph would drop when I add the new salt water in. Is this unnecessary? I keep a small bag of crushed coral substrate in the filter. Is it okay to leave the crushed coral in the mixing bin for a few water changes? I let it dry out completely each time.
