View Full Version : Waterproof lighting for scrubber

06-21-2012, 12:42 AM
Hello all

This is a sub project of my first SW tank project: I came to a point where I need to have immersed lights for the scrubber so as to be able to light both sides of the screen.

The solution I found was to encase the floodlight in a 3/4 in. PVC pipe with bends as per the drawing below and silicone the entire structure for waterproofing

In this schema you can see the general idea:


and this is a pic I took of the bulb in the tube.


I figured I could seal the entire cross section with aquarium safe silicone.

the bends in the tube would ensure that no section of the tube allows water through and they allow the cables to go out of the sump.

The overall structure should look something like this:


Has anyone attempted such a thing or tried anything similar? any help/recommendation is more than welcome guys :)

06-21-2012, 01:29 AM
Immersing AC into salt water is always very dangerous amusement. Only small , even microscopic leak and boooom... dont event want to imagine that...

06-21-2012, 01:36 AM
Immersing AC into salt water is always very dangerous amusement.
Only small , even microscopic leak and boooom... dont event want to imagine that...

indeed...this is my prime concern and one of the reasons I posted it here...to see if anyone has had any luck with such a build and get any feedback from their experiences...

i figured the "weak" spot in the design was the joint between bulb and pipe...so im looking into ways of insulating this part...

06-21-2012, 05:52 AM
I'd consider just putting a clear box of some sort in the sump to hold the light. Make the box taller than the sump so it can't flood. Something like one of those acrylic spagetti noodle storage containers might work, and you could line it with foil as a reflector.

06-21-2012, 07:21 AM
how about if I build a small glass cube for the bulb...the reflector is not needed as it comes with its own reflector (CFL floodlight). I would place the bulb in, and have the electrical cables go out through a small opening (say .5cm x .5cm) and then silicone the whole system shut to make it waterproof...cure it a couple of days in a bucket of water and then insert it into the system... glass could be cleaned with vinegar and water whenever it gets too clouded.

to change the bulb, use a sharb blade to tear off silicone from one side (front side), replace bulb and silicone back...

I figure I would always have two extra boxes ready so that I can take one out and place the other while the changed bulb box is cured...

what do you think?

06-23-2012, 12:03 AM
Personaly I think its not worth the risk.

07-05-2012, 02:01 PM
I am new to the forum, and have a similar problem (I have a Rubbermaid sump, so I cannot shine light thought it). I found these LED light that can go underwater, I am just not sure they would be bright enough. http://www.drsfostersmith.com/product/prod_display.cfm?c=3578+3733+10704+24833&pcatid=24833

07-05-2012, 02:06 PM
Wrong color; not enough watts.

07-05-2012, 02:08 PM
that is what I thought. Just was looking to see if anyone make underwater lighting.

07-06-2012, 01:48 AM
Well following morgans advice, I am building a glass box...taller than sump...with mirrored walls...will have the lights in there...


All sides are mirrored except the side facing the screen, which is open to allow lights to shine through.

The top can be opened and closed via a removable mirror section to allow light placement/adjustment etc. I may even put a couple of small fans up there and forego the lid all together because I am assuming this will heat up considerably if hermetically closed...

I made it taller than sump to guarantee that no water will get in...

Inside, you can use egg-crate or even glass mirrors for dividers in case you want several rows of lights ( I made my box big enough to allow for scalability in case I need a bigger screen in the future)... it can take two rows of three linear CFL each.

problem would be with glass screen being clogged with algae and other buildup (salt etc) which means u need to clean it frequently...another problem is as stated above, the box will heat up thereby heating up the water in the sump...better ensure some way of cooling or perhaps light your screen at an opposite schedule to your DT (when screen off --> DT on and vice versa)

if you dont want to have mirrors on the inside, you can use floodlight CFL which come with a built in reflector but I think those are only good enough for small screens as the light would be somewhat focused in a small spot...

I am taking my time right now as long as the wife is not complaining about all the wires/cables/lights/tubes that are surrounding the tank :) once complaints increase, I will eventually have to tidy things up I guess and this is when the box will go in :)

I must add I am in testing phase right now with a one sided screen lit from the outside of the tank...

here's a pic of the current lights

and the "cooling system"


07-06-2012, 05:29 AM
here are some pics of the box while the silicone dries out...




It is rather big...but i figured why bother every time I need to upsize my screen...plus I had the glass and the mirrors so...

next ill water test it, fit the bulbs and let it cure for a while before I put it in the sump.

07-25-2012, 08:28 AM
I still think a plexi or glass box filled with mineral oil and LEDs could work out. Lower voltage, not as bouyant, and even if you did spring a small leak, which I think is HIGHLY unlikely if you are careful, I dont think mineral oil in small amounts would hurt a reef tank.

02-02-2013, 10:01 PM
How about fiber optics? It will keep all of the electricity out of the water. You can also use spa light housings. 12v transformers/spa lights are also available.

02-08-2013, 05:14 AM
I've not yet had a need to. But castable plastic is a good option perhaps. Ive been waiting for the day encasing LEDs in clear plastic would be needed so I could do it. Ive used the product before. Pretty easy to work with. Smooth-on make a whole array of it. Thier customer support is fantastic and would help select something suitable and always seem to have the answer. Good material for the DIY guy to be familiar with anyhow.