Algae Filtration... This may not be something you may have an opinion on or care to, but I stumbled upon an aquarium equipment manufacturer found at <A href="http://www.eztank.com">www.EZtank.com</A>.   They claim that it is algae, not bacteria, that is nature's main river, lake, pond, and ocean filter. One would say well duh, plants do absorb some excess nutrients from the water, but with this system of filters, apparently it absorbs virtually all.  Their system seems to really make sense but it could also be just another gimmick (Though they have been in business for 15-20 years).  The website has quite a bit of reading but if you are like me , you probably will read anything aquarium related you can get your hands on!!  If you download the information package for free it really goes a little more in depth into their processes, equipment, and theories.   Just thought it you guys may find it interesting and maybe would have an opinion.  Thank you for all the hard work on WetWebMedia, the single best source for information on the net!! (I know Bob would disagree saying we should utilize multiple sources). <Thanks for sharing your discovery. Yes algae filtration is a proven concept, and it has its advocates (Adey and Loveland in the saltwater arena, for example) and detractors. Algae "scrubbers" have been used in closed systems for some time, with good results. However, as you surmise, algae does not do it all. IMO, an algae "filter" is a good supplemental system, but you'd still want to employ some other chemical, biological, or mechanical filtration as well. One of the "knocks" against algal filtration in reef systems is that it can cause "discoloration" of the water. This can easily be removed with activated carbon (chemical filtration), and aggressive protein skimming can help remove excess organics from the water (mechanical filtration). I agree with the "natural" philosophy of reef keeping (and fish-keeping in general), but it's always nice to have multiple techniques to help out. Regards, Scott F>

Disease control, role of environment, danger of generalizations and "what's a refugium"? Bob: Am being told:" Disease in a natural environment is rare, especially when an algae/refugium is used as algae produce a ton of elements that aid in fish disease immunity." <Mmm, not to be too much of a stickler... but diseases occur less frequently and are more mild with such systems employed... but I wouldn't use the term "rare"... in point of fact, many algal scrubbing systems are quite prone to water quality problems...> What is such a refugium and how do you build or acquire if you agree with this opinion as expressed by Euro-Reef Customer support when inquiring about Ich control with one of their skimmers and live rock or sand?  <Mmm, please take the long read here: http://www.wetwebmedia.com/refugium.htm and the linked FAQs (blue files above)> Thanks Again for your considered and knowledgeable advice. Sincerely, Stephen Pace <You're welcome. Bob Fenner>

Water high in sulfates (algae control) Good morning- We have a 460 gallon aquarium with a metal halide, 717 watt light. We have a severe hair algae problem. Our water may be high in sulfates and we've since gone to a reverse osmosis filter and a water holding tank. Our next water change will be the first with this new approach. Will this help to alleviate our algae problem and short of manually taking off the algae, is there another solution?  <I doubt if sulfates are a primary contributing factor here... phosphates, nitrates are typically limiting influences... Many other solutions exist... in broad categories: other nutrient limitation, competitors, predators, allelopathogenic activity (mainly from macro-algae culture...). These are covered in "Algae", "Algae Control", "Algal Filtration" sections and associated FAQs files on our website: www.WetWebMedia.com> Also, we're having a difficult time maintaining a snail population. Is this because of the water?  <Perhaps... do you have sufficient biomineral concentrations? Alkaline reserve? Your snails need both... Maybe they are being preyed upon by another life form... Many possibilities here. See the "Marine Snails" sections on the WWM site as well. Bob Fenner> Any advice would be GREATLY appreciated. Thanks, Doug

hole in the head I have a 125 gal. fish only tank with about 100 lbs. of live rock. For lighting I have four 48 inch, 40 watt tubes. Two of which are 10,000 k daylight and two actinic blue. My fish consist of one fully grown black Volitans lion, a yellow tang, a Sailfin tang and a hippo tang. The yellow has been in the tank for several years and shows no sign of hole in the head.  However, both the hippo and the Sailfin are suffering from a progressively bad case of it. I feed all of the tangs Spirulina flakes twice a day. What can I do? Can the disease be reversed? >> This degenerative disorder can indeed be fought and reversed... Though there are proponents of other major sources of "cause" (stray electrical potential, protozoan infestation), I am of the water quality and nutrition school... Do look into the benefits of algae and mud filtration (as in down in a sump) and adding multi-vitamins and iodine to your food stuffs ahead of offering them.... and do take a look at the pieces on marine diseases... stored at www.wetwebmedia.com Bob Fenner