So I decided to apply a melafix treatment; 6teaspoons daily for 7 days in my 65gal malawi tank. The reason for this was I just dont know what diseases or parasites these fish could be having and as to why some were dying. So better preventative than tackling antibiotics and the likes. Monday will be day 7; I imagine I will re-introduce the carbon into my astro and aquaclear filters but should I perform a water change? The tank definetely looks like it needs a cleaning (but I will leave the algae that is growing on the rocks for the cichlids to nibble on). I'm just worried that by doing a water change right after the treatment is over; I would lose mahy of the beneficial results of the melafix.