Reef Discussion

MagicJ

Moderator
Jul 11, 2011
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Hobart, Tasmania
David, I just had a look at your tank setup in your TJ - you should be able fit your LED's into the space available. Remind me - what LED's and heatsinks are you looking to get?
 

MagicJ

Moderator
Jul 11, 2011
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Hobart, Tasmania
http://www.rapidled.com/servlet/the-54/24-Ultra-Premium-LED/Detail with 4.25" x 23" heatsink - I figured a larger heatsink might help keep its temp down, and help compensate for how close to the water it will have to be.
Trust me, driven at a sensible level (around 750ma) heat will not be an issue ;) As far as mounting the heatsinks, why don't you mount two pieces of wood either end of the tank to create a ledge and sit the heatsinks on this ledge?

Something like I have done in my temporary hood - you can see one end of the ledge at the top of the photo.
You could screw a couple of brackets onto the heatsink to stop it falling in!!
ai538.photobucket.com_albums_ff341_ShaneJ05_LED1.jpg
 

DavidS

The Resident Loony
Jul 17, 2011
3,337
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Ballarat, Victoria
If the heat isn't too bad, my thought was to work the opposite way around - put a couple of spacers between heatsink and the lid, and attach to that - then when I open the lid, I don't have the light to contend with as well when I need get into the tank. Moving the current T5s annoys me on a tank this small - so being able to lift the lid and have the lights get out of my way is an obvious plus - I was just worried that it might be too warm to do that.
Looks like you've got some serious water movement in there :P
 

DavidS

The Resident Loony
Jul 17, 2011
3,337
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Ballarat, Victoria
Before anyone mentions it - yeah, I need to seal the boards around the top. The light is further back normally - just up the front to give the hammer some light. That lid is yellow tongue flooring material - so it's thick, bloody heavy, and doesn't care about water.
 

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MagicJ

Moderator
Jul 11, 2011
9,650
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Hobart, Tasmania
OK, so you have a flap which you can open for feeding etc and then there is a lid on the top of the cabinet?

If you are thinking of fixing the heatsinks to the lid you may have some heat issues but there might be some solutions :confused:

Heatsinks work by drawing heat away from the LED's and then dissipating the heat via their large surface area. I would have some sort of standoff between the heatsink and the lid (hope you get the idea) so that the heatsink is not hard up against the lid. I would then drill a series of holes in the lid along the side of the heatsink to create some air movement and allow the heat to escape upwards.
 

DavidS

The Resident Loony
Jul 17, 2011
3,337
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Ballarat, Victoria
There is a front flap for feeding and minor stuff. Lid on top to get full access, and messing around with all the support stuff that's up there.

I was thinking of putting in a spacer of some description between the heatsink and lid - perhaps 30mm or so, and it wouldn't be difficult to create a grid of holes in the top. Anything that could save me having to put fans up there would be a plus (though I could do this if I really, really needed to).
 

MagicJ

Moderator
Jul 11, 2011
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Hobart, Tasmania
Do you need the lid? Open tops are pretty normal for reefs to help with gas exchange etc.

If you need to keep it then I think the proposed plan would work.
 

DavidS

The Resident Loony
Jul 17, 2011
3,337
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Ballarat, Victoria
I like to keep that lid down - there is also glass over the tank as well. I put it on there once I put a blenny in just so I could feel out if he was a jumper. He doesn't seem to get bothered too easily, so I reckon I might remove that soon.

Heat is an issue here - so keeping the lid down actually helps me keep the tank temp up. I loose a degree if I have the wooden lid up for any period of time. The room itself is kept at 18C - I keep the gas heater permanently on, otherwise it gets to within a degree of the ambient temps - I have walked out to that room and found that it's 1 or 2 degrees in there in the past.
Whilst I'm using a ridiculous heater for a tank that size, I'd rather try to minimise the need for electronic heating any more than necessary.
 

MagicJ

Moderator
Jul 11, 2011
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Hobart, Tasmania
It gets pretty hot there in summer though :confused:
Is the glass clean - is that restricting the light getting to your hammer (:offtopic wrong thread)
If you are prepared to drill some holes in the lid I think you LED's will be OK.
 

MTG

Moderator
Jul 10, 2011
10,664
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Gold Coast
cant you just do strips of leds and screw it in to the top of it. like what shane did with his U channel?
 

DavidS

The Resident Loony
Jul 17, 2011
3,337
1,033
Ballarat, Victoria
It gets pretty hot there in summer though :confused:
Is the glass clean - is that restricting the light getting to your hammer :)offtopic wrong thread)
If you are prepared to drill some holes in the lid I think you LED's will be OK.
Haha - last summer it wasn't hot for long! The one before that was crap. I think if next summer looks hot I may have to look at how long the lights are on. I may also get desperate enough to buy a small chiller for that tank, but that's a different issue.
Glass is clean.
 

marineclass

Member
Jul 12, 2011
604
77
Gold Coast
Magic - how do you find the U channel works as a heatsink? Does it keep them cool enough? And how many do you have attatched to each channel?
 

MTG

Moderator
Jul 10, 2011
10,664
2,149
Gold Coast
lets must allways be soldered. they need good thermal conduction. from what i have been told (talked to shane about his setup) it works great only gets warm :rolleyes
 

MagicJ

Moderator
Jul 11, 2011
9,650
3,761
Hobart, Tasmania
Magic - how do you find the U channel works as a heatsink? Does it keep them cool enough? And how many do you have attatched to each channel?
Before building mine I had a discussion with Dave at Reeflections Aquarium in Melbourne who built all of the LED lights for the shop tanks. Initially he used the standard finned heatsinks but soon realised that these were overkill for his situation and reverted to using aluminium channel. From memory, the channel he used was smaller than me but he had his LED's spaced a fair way apart.

In my situation, the channel is a relatively cheap alternative. I am currently driving them at 850ma because they are located a bit higher than their final location and they get warm, but not too warm to touch. I plan on reducing them to 750ma when I finish my new hood which will reduce the heat ouput further.

I mentioned my situation -I live in Hobart so our summers are not generally extremely hot; my tank is in a relatively cool part of the house; we have a reverse cycle air conditioner in the room which we use when it does get hot. Your situation may be different ;)

I currently have 9, 19, 20 and 12 led's on the 4 channels which are all 1200mm long.

:)