Hi my tank has finally cycled going to do a 90% water change tonight ready for fish tomorrow. I have a lot of brown alge in the gravel. Would it harm to gravel vac it away or could this mess up the bacteria? Any advice is as always much appricated
IMO and some other members might say this. Even/after your tank is cycled you need to wait 1 - 2 more weeks till you can touch the tank, so if you did a water change thats allright but don't do any more cleaning, just testing the water.