Tetra Pond UVC-18 GreenFree UV Clarifiers, Up To 4400 Gallons, 18-Watt, Green

I have 1200 gallons pond which had not had a water change for about three years, and was over populated. As soon as the temperature rose above 60 degrees this spring the water turned pea soup green, and I could not see any of the fish. I drained the pond, sprinkled “Green Clean” powder over the drying algae, and let it sit for over one hour. I used a garden hose to wash away the dead algae ( including string algae) from the rocks and the liner, and I then drained the pond once more.I refilled the pond, and reintroduced 50% of the fish population. Within one day the water started to turn green again. I added some concentrated barley straw extract, and then installed the Tetra Pond UVC18 – UV clarifier. Within two days I was able to clearly see the bottom of the pond three feet down. It is now late April and the water lily leaves are already floating on the surface. In a few days I will introduce the water Hyacinths, and water Lettuces which usually keep the water clean during the summer. I will stop using the UV light as soon as the plants are established.Ten days later the pond water is still clear. However, I am noticing the rocks starting to get a green tint again. I am rating the Tetra Pond UVC18 only four stars because the clips holding the bulb are not strong enough to hold it in place, and it falls away from its socket when I insert the bulb in its holding tube (even after I bent the clips inwards), I also had to wiggle the wires coming out of the transformer to get the unit started. I rate the “Green Clean” five stars for removal of string algae, and other algae. However, at this point I am not sure that the product will prevent algae re-growth.By the way, I use a 1 ¼ coiled hose to circulate the water away from the pump. After much difficulty (plunging it in hot water) I was able to slip the hose over the UVC-18 inlet connector. However, I was not able to stop a small water leak by tightening the ss collar. I purchased a smooth 1 ¼ tubing to replace a section of the coiled tubing and was then able to prevent the unit from leaking

I originally ordered the 9 watt because of the gallon size of my pond. It didn't work. Sent back ordered the 18 watt which is supposedly good for over a thousand or more gallons than my pond. This one will not keep up. I literally have algea floating around all day but about 1 hour before sunset which is 9:30 pm in summer it'll catch up and clear the water. We'll until about 10 am the next day and same thing over again every day. I suppose I should have ordered the biggest algea sterilizer they make for my 850 gallon pond. Which is like 3 or 4 times the amount of water I have in mine. Well it'll be fall soon I suppose and it'll work great then. I do believe. I have used this brand for many years and was happy until here the last 2 years. They must be buying sub-par junk from another country now. At $180.00 I expected much more. Now I'm stuck with a high priced piece of junk that won't do the job I paid for. I should have bought a off brand saved myself 100 bucks and had the same problems...

I have a 10x12’ koi pond and used to use Danner Pondmaster 40w I’ve light. Over the last year spending hundreds of dollars on ballasts and lights and having so many problems with it I decided to switch. I did a lot of research before deciding on Tetrapond. It got a lot of good reviews.I’m very happy so far with the Tetrapond. It was easy to install and is doing a great job and costs a lot less. Just don’t submerge it in water.The pond is crystal clear and the fish are happy! The bulbs and glass sleeves are less than half the price of Pondmaster. So much to like about Tetrapond. Plus it has a 2 year warranty. I highly recommend this product.

I don't usually write reviews on products, but this one it an exception. I have a small pond (about 3000 gallons) and can never keep it clear of algae. Over the years I have spent countless dollars on chemicals, barley bales, etc., but none of it worked. I read the reviews on many different brands and settled on this one because I have purchased this brand before and have not yet been disappointed. In a little over a week (minus 1-1/2 days without power due to a storm), I can now see my fish and the bottom of the pond. I purchased the 18 watt to make sure it would work. It does work great!!!! I would recommend this to anyone and I had no problem with installing on my current waterfall. I had everything I needed and installed in very little time and with ease.

This UV light has been incredibly frustrating. Installation wise, I measured the inlet/outlet size and planned to hard-plumb it into my system between the pond and filter. I cut apart my current line and cut in threaded fittings.The trouble began when I tried to thread on the PVC adapters. The size is 1 1/4" but the threads, not standard pipe threads. So you can't screw a standard plumbing fitting onto these. You are forced to use a hose & clamp. Fine. But good luck finding a good reinforced 1 1/4" hose at your local hardware store that actually fits. I ended up using radiator hose from my local auto parts store.I plugged it in and it worked fine. I left it to run overnight. I am using it to help clear up a green pond before we head into the winter months. This morning, it won't light.So yeah, frustrating. You can't plumb it in using standard pipe thread fittings and reliability seems really low. If you buy this, plan to get some 1 1/4" ID reinforced hose and install it so it's accessible and easily removed. That way, when it dies on you in the first few days, it'll be easier to replace.

Hooray! I can see my fish again! We had water so green you could have walked across it and now clear! That said, I had to replace the original one we ordered because I think it had a faulty ballast and was burning through the bulbs.At first we thought we were getting bad bulbs. The return process was easy and no issues and this one seems to be working fine. We installed the first one around 4/15 and even with little glitches with the bulbs, we have clear water in less than a month!

Two weeks and my pond is still green but.. seems like it gets a tiny bit better every day.

Did not work for me but will try again in the spring