# Fish Pond filter with UV sanitizer lamp - swap for LED sanitizer suggestions

#### ThePanMan

Joined Mar 13, 2020
367
Currently I have a 100 gallon pond (will be upgrading perhaps this year). The filter kit comes with filter elements, bacteria media and a UV-Clarifier lamp. Oh, and yes, of course, a pump. It's not possible to tell if the UV lamp is working without pulling the filter out of the water. I don't know if there's some sort of pressure switch that prevents the UV light from being active when not submerged. And for some reason those fluorescent type UV-Clarifier lamps seem to not last very long. Also, finding a replacement lamp - so far I've been unsuccessful. So I'm wondering if it's possible - or ill advised - to replace that fluorescent lamp with a UV lamp. Anyone have any suggestions? Recommendations? Cautions?

The current unit appears to run on some sort of ballast.

I don't know that it's critical to replace the ballast (if that's what it is) but I have no other way of verifying it's working. The unit that houses the lamp is at the bottom of the pond and difficult to reach on short notice. This (tracking disabled) appears to be a replacement lamp but I don't know how to get to the old one. And if I can figure out how to access it - I'd like to replace it with an equivalent LED type UV-C lamp.
The pump:

Somewhere in the garage - gotta go find it - is an older unit I can experiment with without putting the fish at risk. I'll update as I learn things about this pump.

#### ThePanMan

Joined Mar 13, 2020
367
Well, OK, I found the old pump. Bad news - it doesn't have the UV assembly.

#### Tonyr1084

Joined Sep 24, 2015
6,887
Have you seen this?

#### ThePanMan

Joined Mar 13, 2020
367
Thanks.

#### ThePanMan

Joined Mar 13, 2020
367
OK! Good news! Found the old Fluorescent UV lamp holder. Seems you just pull the glass off. Will have to silicone the seal back when done. Lamp change is easy enough. But still want to replace Fluorescent UV-C with LED UV-C.

So can anyone make any suggestions on how to modify this thing? Remember, it has a ballast that will need to be chopped out of circuit and attached to some sort of DC circuitry. Depending on the specifics of the LED Data Sheet and the final voltage to be chosen along with a current limiter - - Oh, wait; Think I saw a driver on that webpage Tony gave. Hang on for dimensions of the glass tube.

. Glass tube ID is 1 .25" diameter. Depth =2.858".

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#### Tonyr1084

Joined Sep 24, 2015
6,887
Does this look like the lamp in your glass tube?

#### Ya’akov

Joined Jan 27, 2019
5,663
UV-C LEDs are expensive and unusual. Have you sourced them already?

#### ThePanMan

Joined Mar 13, 2020
367

#### ErnieM

Joined Apr 24, 2011
8,294
Sorry to be late to the party. I have two ponds that need UV to keep floating algae at bay. I buy these or similar, get a year or two out of them. I have replacement bulbs but by the time they need that the pump or water seal is shot anyway. Oh, and they come with a little window to check the UV is on.

#### ThePanMan

Joined Mar 13, 2020
367
Thanks ErnieM expecting LED UV-C and driver module to arrive today.

That pump/UV unit is just a little over the cost of replacement lamps for my pond filter. What concerns me is deteriorating seals. Also, your unit isn't a filter. Concerned about that as well. But thanks for the link. It could be an "Add-On" thing I do when I build a bigger pond. It's just that the UV LED's would last much longer and I'd have a greater sense of security with my pond remaining free of algae.

I'll definitely be posting pictures of the build once I get the parts.

#### ThePanMan

Joined Mar 13, 2020
367
Finally got the parts. And they sent the wrong LED module. I've sent them an email. Let's see how long it takes for them to respond.

#### ThePanMan

Joined Mar 13, 2020
367
OK, just got the right LED unit. I'll put it together in the next few days and post some pic's.

#### ThePanMan

Joined Mar 13, 2020
367
So far I have the LED UV-C mounted on a heat sink. The connection to the old fluorescent base has a bridge rectifier in it because I don't know which way the LED will end up being plugged in. Since there is no predictable way to connect it - the BR is there for protection only.

Later today I will apply thermal grease to the heat sink and glass tube so that it radiates its heat into the pond water. I've already tested for illumination and yes, it does light up. I tested it with low power, not the 150W the driver will deliver.

The project may be delayed a day or two, there's something up with one of my pets and we're taking her to be looked at. Hopefully all is well enough and can be easily treated. Cats seem to know when they need bed rest, and that's what she has been doing.

Will post further pictures either tonight or tomorrow (likely).

#### ThePanMan

Joined Mar 13, 2020
367
After basic assembly and testing I must say I expected a lot more light energy from this. Maybe I just don't understand how strong UV light is.

Using a 15VDC 500mA wall wart, connected to a "Buck Toot" (BT Driver) 150mA Constant Current driver I get the following results:
BT output into UV-C LED's 87.2mA

Using a 13.8VDC 19A power supply connected to a BT I got the following results: