Need to get smaller gravel vacuum, the one I'm using at the moment 1 min and half a little tank is empty, not enough time to catch most of it out.On start up it’s only ever been an issue for the first three weeks personally. In that time I just get in there and siphon it out. Bucket and hose then refill the tank. Only really messes up slow growers; anubius, buce, mosses, liverworts.... if left to completely cover them. Would imagine it chokes the plant, which begins to break down, giving the fungus something to feed on.
If being really quick about it, just knocking it off leaves etc when draining the tank would be efficient.
Others will tell you it can do no harm and will disappear on its own.
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