paracite control

First I want to apologize if this is on the wrong part of the site. So, as I think many people have done, I bought a Green spotted puffer or leopard puffer from a local shop under the impression he'd be a freshwater fish, but after doing more research than the quick 2 minutes on Google before...

Hi I recently set up a new tank. Should be total water volume of around 650 litres when you subtract sand and rock. I want to purchase a UV to help with parasite control as well as water clarity. I have had Ich, Dino’s and cyano in the past. I am in the UK and torn between 4 different UV...