Hi,

Sorry if this is a daft question but I've found very little about these to be able to compare and fully understand their benefits.

Whilst I understand what each of them does (OK, not so much the RO) I don't understand which of them to consider.

I currently have 1 planted tank and will be in the setting up another much larger tank for Discus over the coming weeks.

I'm not saying I will get any of these items but if I were to have a shopping/wish list, which unit would I want and in what order? What would be the benefit of adding one to my tank(s).

My guess is that the UV is the place to start but I'm not 100%.

My tank is generally pretty good with the occassional bit of algae. I've currently got a hazy tank after a snail died in there and the water went to pot but it seems to be coming back around after a few water changes etc.