[slief]

Originally Posted by ReefKeeper64

Hey Slief, That's interesting that your UV raises your ORP. I wasn't aware of that benefit. So in a sense, UV sterilization is doing some of the same work that an ozone generator does I guess. Thanks!

UV oxidizes organic compounds and by reducing organic compounds water quality is improved. It also removes water born algae and bacteria. Ozone is an oxidizer too with the difference being that ozone uses a gas in direct contact with the water to oxidize organics and sterilize the water where as a UV Sterilzer uses the light spectrum to oxidize organics and sterilize the water. They have very similar results. That said, a crappy, improperly size and improperly setup UV is a waste of money. If you are going to go that route, you get a quality one and set it up right.

When my UV bulbs died on my 114 watt AquaUV, my ORP tanked. I normally change my bulbs every year but this time I had gone about 1.5 years. When my ORP tanked, I started investigating and realized my bulbs had died. I got a pair of new bulbs and my ORP skyrocketed over the course of 10 days. I feed my tank very heavily and have around 70 fish in the system. There are a lot of organics going into my tank which can have a big impact on water quality so for me, ORP has a surprisingly big impact on my tanks water quality over and above it's clarity.

This is part of my ORP graph immediately after replacing my bulbs in April. The ORP went from 275 up to 400 over the course of 10 days. This shows a weeks of graphs. I am a firm believer in the benefits of UV having a properly setup quality UV unit and this is just one of the reasons.



This is a screen shot of my ORP today. No ozone. Just my UV sterilzer. This ORP probe is about 4 onths old and is consistent with the ORP probe on my Profilux as well. I have both an Apex and a Profilux for monitoring and control. I have confidence in the accuracy of my ORP.