UV will have a significant effect only on waterborne algae, not anything that has attached to something. UV is not a silver bullet for alage. It's great for killing green water algae and also for white water bacteria blooms but not for hair algae or biofilms. Also, many gardeners -- some of the best inthe hobby -- do just fine without any UV at all. It might be no more useful than a diatom filter. By that I mean this: probably the best times to use one are when introducing new fish and when fighting cloudy (green or white) water. One clear benefit of leaving one running all the time is that the quartz sleeve usually doesn't need to be cleaned -- the UV keeps any biofilm bacteria from attaching to it. Otoh, you have to buy UV bulbs more often if you leave it running. One could argue that running one any time you scrape the algae off the glass or otherwise stir up the tank helps kill off a lot of undesirbable stuff, including the algae stirred into the water. I suppose this is true, but there isn't much evidence for that argument either. I don't know of anyone that has demonstrated any adverse plant effects from using a UV. I wouldn't assume that there might be any unless some such demonstation appeared. I'm going out on a bit of a limb there but I'm not alone on the limb. Practical examples say that they don't hurt your plants. They haven't hurt mine in any way that I can see. Well, at least let me say this, my plants don't do any better without one than with one ;-) sh --- Steven Olson <stevenkentolson@yahoo.com> wrote: > Along this line, do you feel that your plants are > doing well? There is so much traffic about algae > problems we can pretty much figure that's significant. > Is the UV eliminating algae problems for you and your > plants are growing well? I'm kind of taking a bottom > line approach. Would be interested in the technical > discussion as well, but without hard data that often > ends up in la la land. Fun to speculate about but not > so useful really unless there is some data or someone > very technically strong in the area. > > > > > Date: Sun, 28 Dec 2003 18:36:42 -0600 > > From: "Aaron Glass" <aglass@wi.rr.com> > > Subject: [AGA Member] UV Sterilizers > > > > Good question here. > > > > I am running multiple planted tanks and I use UV > > sterilizers for nuking any green water problems. > > > > I have read and heard that using a UV sterilizer on > > planted tanks is not a good idea since it evidently > > oxidizes trace elements. > > > > Does anybody have any up to date information on > > this, experience, or know if it has been proven in a > > lab or controlled environment? > ===== S. Hieber __________________________________ Do you Yahoo!? New Yahoo! Photos - easier uploading and sharing. http://photos.yahoo.com/ ------------------ To unsubscribe from this list, please send mail to majordomo@thekrib.com with "Unsubscribe aga-member" in the body of the message. Archives of this list can be found at http://lists.thekrib.com/aga-member/