DIY LED Light Questions

[Cal_stir]

are u using the fixture as a cover? saltwater and aluminium don't mix to good, you will have a lot of corrosion, aluminum angle or square tubing are good for frame, dissimilar metals will corrode as well so keep it all aluminium.

[Beanz]

Naw i'm using the the fixture to hold down some acrylic sheets that i already have on top of the tank (should i cut some spaces in the acrylic and buy some fans to mount is in it to get more airflow over the top of the tank water? or will a 10 gallon sump with a coralife ss 65 gallon and 10 gallon refugium b enough for gas exchange and such?), ill probably raise the fixture up maybe 4-6 inches and hold the acrylic down and keep the fixture propped up on some 1X1 struts. I think for the fixture imma use L channel aluminum and put the heat sinks in the L, then i was thinking of screwing the L channel onto a 2X4 than putting the same stuff that's on my stand. But before i will cut squares in the side of the wood so i can mount the fans in there. Is this wise to mount the aluminum to the wood? or will it get too hot?

Thanks, Ian

[Cal_stir]

don't cut the sheets, you will get enough gas xchange with sump and skimmer,the fan will keep the heatsink nice and cool, the leds will fail before the heatsink gets hot enough to set wood on fire

[Beanz]

ok thatnks cal, i am gonna do a water test today and c if the pH is changing as a result of the sheets. if there is i might get some screen but the acrylic is doing a dandy job of keeping the zebra in the tank. I am going out today to get the materials for the fixture so i will start posting pics today maybe, i might get a shot of the zebra too if i can get a good shot

[Beanz]

Ok I built the fixture, but have not added the peices for how high it is gonna b. So how high do u guys think I should have the fixture, and should I use 80degree optics for the height or something a little more focused if the fixture is higher.

Thanks, Ian

[Cal_stir]

my fixture is 1 inch above tank with no optics, the leds emit @ 120 degrees without optics, i find this to be perfect for my application, no spotlighting. i remember reading an article about a guy who used 40 degree optics and he had to mount his fixture about 12 inches above his tank to eliminate the spotlighting effect, my guess with 80s would be @ 4 inches.

[Beanz]

Ok I will try that out, do u think that the 24 LED with dimmable driver kit will be enough light for the back of my tank (6") or would it b better if i saved my money and bought the 36 Led with dimmable driver kit?

[Beanz]

This is a little off track but this is my new little zebra eel and thanks for the help, please keep the info coming it is really giving me ideas and an understanding of lighting. O and i need to get some calcium additives and a test, if i get some Kent Marine Liquid Calcium do i need to dose kalkwasser? I am looking to keep SPS near the top of the tank and LPS near the bottom.

Thanks, Ian

[fkshiu]

Contact Ron99 on here. He's built his own DIY LED fixture that's already spreadin' the PAR wealth.

[Ron99]

Ian, figured I would continue answering your questions here instead of by PM. I think for your sized tank you will need at minimum 48 LEDs with 80 degree optics to provide sufficient PAR for SPS corals. Personally I would go with 54 to 60 LEDs. For comparison, I used 80 LEDs with 60 degree optics on my 48" x 18" tank in 4 rows of 20. I am currently running the blue LEDs at 100% and and the white LEDs at about 80% and have around 500 to 600 PAR 1/3 to 1/2 the way down my tank which is 20" deep.

With your tank being 12" wide rather than 18" you could drop one row and do 3 rows of 16 to 20 LEDs. The more you do the higher the PAR will be. With 24 to 36 LEDs you will have to run them without optics and may not have sufficient PAR for many SPS.