Last year I got tired of looking at green water & got a UV & my water was clear within a week or two.

Just sayin.

I'm new at this ponding thing so haven't had the personal experience of others. But if your floating plants are doing well, I suspect your water has a lot of nutrients in it which is also feeding the algae. If the water isn't getting the nutrients from outside sources such as lawn runoff or exposed fertilizer spikes in potted pond plants, then muck on the bottom is probably the source. Stuff can get between the cracks in the rocks and build up beneath them. I think most folks on this forum will suggest removing the rocks on the bottom for easier and more thorough cleaning. uV may kill off the suspended algae and clear the water but won't address the problem of muck under the rocks which can apparently be a breeding source for non-beneficial bacteria.

My fish pond has had rocks on the bottom for over ten years with only one green algae bloom. Rocks don't cause algae.

I'd add some submerged plants such as anacharis or hornwort. The only time I did have an aglae bloom was when I cleaned too many of them out one fall and the next spring I had two weeks of pea soup.

If you are in the Portland area, I'd be happy to give you some anacharis. I've got tons. I've got extra azolla and parrot's feather too.

Hey buyorsell888 I am in the Portland area and would love to get some from you as well as talking one on one. My name is Tom and my cell # is 503-781-4427. This green water is driving me nuts. What about vaccuming the rocks once in awhile? I'm thinking that would be a good solution until it can balance out, am I wrong?

Thanks,

Does your system contain a biofilter? A place for beneficial bacteria to grow that is part of your water flow system. Bacteria can grow in many places, but it's good to provide a surface for the bacteria and have your pond water flow through it. Plastic balls, nylon ribbons, or bottle caps are all good.

I don't think the bottom rocks are causing algae and their collection of bad bacteria would probably depend on your fish load.

A UV sterilizer will not remove the cause of your suspended algae, but it will eliminate the algae if properly sized. My pond is 1,000 gallons and a 25 watt UV lamp works very well when needed.

Johnkr - My biofalls consists of 6 filter mats at the top of my falls. I did a complete clean out in the spring and it was crystal clean from March through mid June and now I can't see the bottom. I only have about 5 comets so my fish load is nothing really. I've been looking online a pond vaccums thinking that may work. I hate to have someone come out and install a UV light but I may have to. My pond is the same as yours about 1,000 gallons.

Redcorvette, installing a UV light is not a task you would need to have someone else do in most circumstances.It is usually a fairly straightforward installation if you can access any tubing or you can add a small pump dedicated to running it.
Your pond is just about the same size as mine and until I saw one that could be hidden easier on sale last year, I used an 8 watt Laguna UV that did the job quite well. I won't have as much difficulty locating and expense replacing the bulb either. I broke my back a couple of years ago so I have some difficulty getting to things but managed this changeout fairly easily.
I was a bit startled to see you post your cell #. It can get you all sorts of problems to do that. You can reach that poster through his e-mail by clicking on his member name at the start of his post. It gives him a choice of responding or not. Sandy

Filter mats are what I would call a mechanical filter. They remover particles from the pond water. Although they also provide a surface for beneficial bacteria to grow, they would not be my choice for a biofilter. The mats have to be cleaned. If you use chlorinated water to clean them, you will kill the bacteria. Even if you use pond water, the bacteria will still get disturbed.

If you add something like plastic bottle caps, perhaps under the filter mats, they would provide a surface for the bacteria to grow. Since the bottle caps would not collect dirt, you would not have to clean them and disturb the bacteria growing on them.

Bottle caps are just one of many materials that provide a surface for bacteria to grow. I use plastic balls and nylon webbing.

If you do decide to purchase a UV system, be careful not to underestimate the wattage of the lamp. If the lamp is not strong enough, the UV will not function correctly and you will have to purchase another one.