I partially agree with you. Algae is present if conditions are right for it. Algae needs sunlight and nutrients. If you shade the pond, algae has a harder time growing but it can still grow. If you have more nutrients in the pond than the bio-filter can handle, the result is food for the algae. Food is provided in several ways. Overstocking means too much fish poo and algae loves that. Feeding too much also means excess nutrients for the algae. Mulm build-up on the pond bottom is probably one of the biggest offenders. So to really eliminate algae, make sure you are not feeding it. Keep the pond bottom clean of all mulm. Don't overfeed and don't overstock, and most importantly add bio-filtration (not plants). I know MANY people who are keeping large healthy koi ponds using their UV lights for only a short period in the spring while the Biofilter is getting up to speed. Once the bio-filter is going well, the UVs are shut off for the rest of the season. My own pond is a good example. I have 9000 gallons and feed 40 pounds of high quality koi food every 5 weeks. I use my two 57 watt UVs for a short period in the early summer, and occasionally if the water temperatures get high for extended periods. Other than that, I don't need them.

Business is business. They need to make money to stay in business. They make money by selling stuff. The more they sell the more money they make. They will recommend UV lights, barley straw, bacteria, fancy filters, and mysterious enzymes because they make money on these things. If you have lots of unneeded money, have fun shopping. But if you don't have money to burn, try adding plants. Plants are cheaper and will work well to control algae. They look good and can be obtained locally. You can often get some from other ponders. I kind of enjoy watching my plants grow.

This is addressed in the FAQ section (link below), but you explained it all very well, Watershaper. It's also been addressed MANY times in posts-gone-by, but most new folks must be too panicked to search or check the FAQs.

One other thing to add, albeit not at the top of the list, is aeration. There are perfectly clear ponds with no water movement at all, but aeration is something to consider, if necessary.

Plants are the #1 option, in my opinion...that is, after the usual time frame has passed when a pond should be allowed to "season" itself. People are so used to quick fixes these days that many won't hesitate to start adding bottled conconctions, when none might not be needed.

I'll be clipping your post, WS, and with your permission, as well as my patience (:D), I'll quote it when newbies require. :)

Brenda

Here is a link that might be useful: What do I do about algae or green water or string algae? FAQ

I agree with everyone. I do a lot of maintenance and I would guess 70% of the algae issues (in my specific jobs) are caused by overstocking fish and overfeeding. Aeration is huge, especially is you want more fish than what is recommended, and often overlooked. And larryl, yeah there are some pond business people that push product to sell, and I'll agree that keeping it as natural as possible is the best route. But not all ponds work out that way number one and secondly don't group us all together. Yeah a lot of...say used car dealers that sell lemons, but not all of them do. I'm sorry if you've had a bad experience, but don't lump us all together.

Ccoombs1 is right, we suggest UV and treatment for the first part of the season because the larger plants take longer to get established. The rest of the season should get balanced out from larger plants. We suggest full-time UVs for those customers that don't want to get so involved with the plants and testing. Plants, fish/feeding, aeration, thats the way to do it, no question. Thanks for the link and your infomation.