waterdrop
Enthusiastic "Re-Beginner"
Partial water changes during fishless cycles really don't have meaning. Partial is only about fish. So, unfortunately for you, the thing I'm thinking of is all or nothing (although since its sand I'd quit before it started sucking out too much, lol.)
If you have a bad back (like me!) you really need to get serious about a Python or a DIY siphon in/out system. When I'm finished draining I just attach the hose to my adapter that attaches to the faucet and do the tank fill. The fill is much faster than the gravel-clean-siphon-out! Absolutely the only way to go with back problems!
~~waterdrop~~
If you have a bad back (like me!) you really need to get serious about a Python or a DIY siphon in/out system. When I'm finished draining I just attach the hose to my adapter that attaches to the faucet and do the tank fill. The fill is much faster than the gravel-clean-siphon-out! Absolutely the only way to go with back problems!
~~waterdrop~~