Underwater refugium lighting

[Brett S]

Just wanted to say thanks again to @Zirco for this awesome idea. It’s been just under two weeks since I installed the underwater lights and I just harvested what would normally be more than a month’s worth of algae from my fuge. Lighting the top and bottom of the algae has increased the growth rate considerably.

 

[Hermie]

another idea is to put a clear plastic cylinder (read: 2 litre bottle) in the center of your algae mass, which would open up an "eye" of water inside the fuge, that way, light can penetrate inside the "eye" of the cylinder. The only downside is that the light must pass through clear plastic before hitting the plants, however, I am willing to bet that diffusion through a clear plastic bottle is A LOT higher than through a 4" mat of algae

sorry if the illustration is lackluster

 

[Joe Rice]

Just wanted to say thanks again to @Zirco for this awesome idea. It’s been just under two weeks since I installed the underwater lights and I just harvested what would normally be more than a month’s worth of algae from my fuge. Lighting the top and bottom of the algae has increased the growth rate considerably.

That's great! I'm harvesting at least twice as much as I was before just to keep the algae from growing over and obscuring the underwater light.

 

[Idoc]

A full month now and the caulerpa is 6" thick and all the way down to the Tunze light.

This looks great! I took my refugium offline due to the light bleed over into other sump chambers and other algae slithering my chaeto! Does this light give less light bleed to other sump areas due to it living upward and being closer to the macro algae?

 

[Joe Rice]

This looks great! I took my refugium offline due to the light bleed over into other sump chambers and other algae slithering my chaeto! Does this light give less light bleed to other sump areas due to it living upward and being closer to the macro algae?

The white acrylic sides of my refugium are slightly translucent so a bit of light might get through but overall I have to believe it'd be a tiny fraction of the light bleed from the overhead light.

 

[Brett S]

So it’s been exactly two weeks since I last harvested the cheato in my fuge and I just pulled out an entire 5 gallon bucket’s worth.

This is two week’s growth since I added the underwater lights. Before the lights it would have been a good 6+ weeks to get that much.

I am still amazed at the difference these lights make and I think this is the best thing I’ve done for my fuge ever. Instead of just floating in the top few inches the cheato was thick and full through the entire 12 inch depth of my fuge.

 

[Keesers]

Very cool thanks for the tip got one in my cart from BRS. Thanks for showing progress that’s helpful to see helps make decisions easier. How long has it been in there now? Is it holding up to salt?

 

[Brett S]

Very cool thanks for the tip got one in my cart from BRS. Thanks for showing progress that’s helpful to see helps make decisions easier. How long has it been in there now? Is it holding up to salt?

I’ve had my three for only a month, but so far they’re doing great.

 

[Joe Rice]

... How long has it been in there now? Is it holding up to salt?

No problems with mine either. Only two months but I don't see the saltwater ever being a problem.

 

[Keesers]

No problems with mine either. Only two months but I don't see the saltwater ever being a problem.

Awesome thanks. Enough evidence for me. Happy reefing

 

[ReeferReefer]

I love the idea and its great to see other people using calurpa instead of cheato too. Grows much better for me.

 

[Joe Rice]

Noticed today that I couldn't see any of the upward shining light in my refugium but quickly realized it was because the macroalgae had grown completely around the underwater fixture so that no light could get out. To give the caulerpa even more room to grow I've moved my big MarinePure block to another section of the sump so that the Tunze light can rest on the very bottom of the refugium.

 

[Joe Rice]

So now, a month after moving the underwater upward-facing Tunze light to the very bottom of the refugium, the refugium is filled top-to-bottom with Caulerpa. With just the top light I had a 3" thick mat of Caulerpa on top; with the addition of the upward facing light I've quadrupled that. In the "after" photo below you can barely see the underwater light as the Caulerpa has grown all the way down to it.

 

[Brett S]

So this post is a year and a half old, but I just wanted to post a quick update. My chaeto continues to grow extremely well with the under lighting. I had one of my three lights fail about a month ago, but Tunze was quick to replace it under the two year warranty. This continues to be one of the best upgrades to my fuge ever.

 

[Brett S]

I just wanted to post another follow up to this thread because I came across another example of how well these lights are working.

I recently did a short blackout, because I’ve been starting to see some dinos in my tank and I wanted to stop them before they got too far. I blacked out the fuge as well.

After the blackout, when I got everything restarted I noticed that my nitrates and phosphates were rising, when before the blackout they were holding pretty steady or even declining.

I was afraid that the blackout had upset some delicate balance somewhere and I was going to need to try to get things rebalanced again. However, two days later when I was working on the tank I noticed that my underwater lights were off. I realized that when I restarted everything after the blackout I forgot to turn them back on. I turned them on again and over the next day or so my nitrates and phosphates started behaving exactly as they did before the blackout. There is definitely a noticeable difference in the nutrient export provided by the chaeto when it is lit from the top and the bottom.