Opinions on UV

[Glostik]

Im looking on getting a UV to help with green water and some piece of mind for free floating organisms.

What is you guys thoughts on UV's?

Also, what wattage am I looking at for my 150 Gallon.

Any recommendation on brand?

Much appreciated
-L

[angelfish83]

UV filters for a tank that size depend on what you're looking to do. For just green water type things you wont need much. If you want to kill absolutely everything you'll want something rediculous like 80Watts of UV. Things like Ich require that much because they are quite large and have a shell, versus things like single cell algae which could be killed by 9W or less.

Brand wise I don't really know which is best as I dont have experience with a number of brands. As in most cases you get what you pay for, and your hands and eyes can sense better quality.

You dont want to pump water through there too fast, as a higher dwell time 'nukes' the nasties harder, just like food heats more the more time it spends in your microwave.

You want to be careful with certain things with it- obviously if a fish got sucked through there, it would be really bad for it, or any invertebrates you WANT to have etc.

Also, certain situations that would otherwise be ok- ie wringing a small amount of bacteria off another tank's sponge into the tank to reseed after (whatever) wouldn't work because the bacteria would run through the UV filter while in suspension and die.

It also creates certain issues for bacteria redistribution in an immature tank, ie, bacteria migrating in water from the filter to the gravel will die if they go through the UV unit.

Its generally a good thing though. It turns your tank into an environment not unlike a microchip factory. its a little too clean. You can't move fish from it to a non filtered (UV) tank that has even a hint of problems because they catch anything like a sponge, having been so clean...

[sophie]

green water.

I'm not convinced this would work every time, but I've got a four-foot tank that gets a lot of slightly oblique though still direct afternoon sun and it went proper, pea-soup green. Daily water changes kept it just about clear enough to see through (though still green), but if left for a couple of days it reverted.

a small, air-driven box filter filled with fine filter floss cleared it completely and kept it clear. The floss does go bright green though!

[chefkeith]

I run a UV sometimes. I recently hooked mine back up for no specific reason. It doesn't replace water changes, but it does help control free floating bacterial populations and some types of algae. Partial Water Changes about 2x per week would solve most problems though, so I don't think UV is all that necessary if you're religous with water changes.

I have Coralife TurboTwist 12x 36 watt UV and use a Rio 2100 (700gph) pump with it. I put a small filter sponge in the intake and clean the sponge about every 2 or 3 days. I'm not sure if the UV does much since my multi tank system is about 400 gallons, but it definately doesn't hurt.

More info about UV's
http://www.drsfostersmith.com/pic/artic ... 24&aid=440

[chefkeith]

I will add that I don't use UV during summer months because my water gets too warm if I do.

[Jim Powers]

I like the Turbo Twist, also. Its reasonably priced, easy to install, and easy to clean.

[angelfish83]

I will add that I don't use UV during summer months because my water gets too warm if I do.

You sure that 700GPH powerhead you run it on isnt contributing just as much heat as the UV bulb though?

[chefkeith]

Angelfish- That's something to think about which I haven't thought about yet. The 700gph pump is 37watts. In the past I was running the UV on a 2026 Eheim caninster filter (300gph) which was used to create flow through the water bridges also.
Recently I discovered that I needed more flow from tank to tank because I was having sudden TDS drops during water changes, so I switched to the 700 gph pump (which has help steady the TDS and water temp ).

I'm not sure what I'll do next year when the weather gets warm. I'll probably have to revert back to the Eheims for the flow if this 700gph pump creates to much heat. I usually don't run any powerheads in my tanks during the summer. It's hard to say what I do as thing are always changing.