You can use a siphon and siphon out the debri or use a powerhead to blow off the debri off the rocks and then siphon out the water. Don't worry about killing those hitchhiker feather dusters, they'll be fine! When replacing water make sure you've mixed the salt in your water (should be RO
water, preferably RO
) for at least 24 hours. Undissolved salt can harm your fish/inverts/corals,etc. Try to match the salinity and temperature as close as possible so the inhabitants aren't shocked. I recommend 10% water change once a week. You can do less depending on how much maintenance you want to do or what your filtration system is like or if you're doing a FOWLR
or reef tank.