Newbie to sw

[hillegom]

Originally Posted by mike31154

Don't think too many people in marine hobby use UV water treatment, but the vast majority do use RODI water for mixing fresh SW & top up. Given the choice between spending $500 on UV treatment as opposed to $250 for a quality RODI system, I'll bet most folks in the hobby would choose the RODI. A side benefit of having a RODI system is having pure RO water available for drinking, cooking, ice cubes, making beer/wine/soda pop, topping up car batteries, radiators.....

+1
RO/DI is way more important. Whether you buy a filter system (recommended) or buy ro water from the store. There won't be any DOCs in the water (dissolved organic compounds). These would fuel algae. Keep looking in the classifieds here and elsewhere and you will buy cheaper. New filters and you are good to go.