Gang@Ukaps Following my thread regarding "Planting a High Tech Tanks" got me thinking today. viewtopic.php?f=38&t=5712#p63343 It was brought to attention yesterday that old tank water is not what you wont within an aquarium when trying to mature a new set, this is due to toxins and algae spores etc. so - why is it recommended that the filter media from a mature set up is washed out or cleaned in old aquarium water - obviously the toxins / algae spore etc are present within the water whether it is from a mature set up or a new set up, so why is it advisable to wash out matured filter media in old tank water surely you are going to imported these particles or substances into the filter media. A better method would be to washed out the media in de-chlorinated water or would it. Regards Paul.