DIY Icecap...its not what you think


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I posted this at a local board...but I will repost here. The prices are in Canadian.

The originals are at

Here it goes......

To produce a lighting system that produces the same amount of light as SHO without an Icecap. Around here an Icecap 660 is about $270 each. Pretty expensive for a ballast that delivers 65W to a F40T12.

F32T8s (the thin tubes - 1" diameter) -- these lamps produce 2600 to 3000 lumens of output and consume 30W of lamp power. So, it produces 86 to 100 lumens per watt.

F40T12s (the thick tubes - 1.5" diameter) -- these lamps produce 3000-3300 lumens and consume 40W.

VHOs (F40T12VHO) -- these lamps produce roughly 6000-6500 lumens of output. I am not sure, but some manufactures say that their output decreases to 4000-5000 lumens after 1000 hours. These lamps consume 110 W.

PC (PL-L 55W) -- these lamps produce roughly 4500 to 5000 lumens of output and consume 55W.

So, we need a F32T8 that glows as bright as VHOs or PCs...say 5000 to 6000 lumens. Based on F32T8's efficiency of 85 lumens per watt, we need roughly 70W or 240% output of F32T8s. There will be some drop off in the efficiency due to heat - so we might need 80W. How do we do that ?

Each output on the ballast is responsible for delivering power to a tube ... lets suppose we hooked up the ballast outputs in parallel. Say, we had a ballast that can drive 4 seperate F32T8s. If we hooked up all the outputs of the ballasts together...we would deliver about 400% output to the lamp -- or drive the power required to drive 4 lamps in to one lamp. Now...this only really works for electronic ballasts and I waive any responsibility if somebody does this...and burns their reef down or injuries themselves. Don't try this on a magnetic ballast...they work on a different principle.

- F32T8 fluroescent tubes (6500K GE - $3.50)
- 4 tube F32T8 electronic ballasts from your local hardware store. I used an Advance REL-4P32-SC - which I got from Home Depot ($30).
- End caps ($3 pair)
- Wire nuts. ($0.20 each)
- power cable - ($3)
How I did it:

I wire all of the yellow wires to one side of the tube and all the red+blue wires to the other side of the tube. This should deliver 4x the output of a single tube. Since 4P32-SC is a standard ballast, it will only deliver 88% of the 30W for F32T8 -- its a standard practice to save power for indutrial/office lighting.
(See attached figure)

~350% (=88% X 4) should deliver 9000 lumens (350% X 86 lumens X 30W). I took a light reading with my camera and I got 6500 lumens. So why a difference...

It turns out that parallel overdriving does always 4x the power of one ballast -- this is due to the fact that it wasn't engineered or design to operate like this. I measured the power consumed by the ballast through the AC outlet, and it was 80W. So, 80W is actually being delivered to the tubes -- so that means 80W X 86 lumens/watt = 6900 lumens. Okay...close enough.

Here's some more info. I'll try to draw up a schematic and email it/post it (or something a long those lines)

The Measurements:
This is for a 90 gal (48x18x24) tank. It has a 5 inch DSB and the lights are 5 inches from the water. I have two overdrive lamps - two 6500K. I will be adding a third, but it will be actinic.

My lighting measurements are the following :

At the surface, 16000 to 20000 lux.
At middle of tank, 7000 lux.
At bottom of the tank. 4500 lux.

BTW, usually 2x175W MH produce this much light It is also...encroaching the 2x250W area.

Temperature...too hot to touch for more than 5 seconds, but doesn't burn your finger off (say, 50-60 degrees C at the tube). Also, its not hot enough to melt those cheap $3 end caps

Ballast...those ballasts are rated for ~110 watts (i.e. 4X30WX88%) ...don't expect them to get hotter than 40 degrees C.

Those Who Dare to Try:
I would start with 1x drive first and measure the power consumed by the ballast. Then, I would try 2x...then 3x and finally 4x. Since each ballast will be different, results may vary. Personally, I would limit overdriving to 90W or less.

So...there you go. 6000 to 6500 lumens for $40....its being working for me for about 2 to 3 months. So..what do you think...please post your comments. Thanks.

- Victor.


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sounds interesting, I have some questions.

Why did you use T 8 bulbs instead of T 12 ? The T 12's are a lot more common (at least in the US).

If the bulbs get too hot to touch for more than a few seconds, I'd be concerned about the cheap endcaps. Esp since you're probably pushing a lot more juice through them than they're rated for.

Any problems with bulb life??

Any other risks assuming the correct ballast is used?? "... I waive any responsibility....if someone burns down their reef or injures themselves."

Could something like this be done with shorter bulbs? For example, using two 2" bulbs in series for cheap refugium lighting ???

Looking forward to your answers, it looks like a great idea,

Hmmm, sounds like a very good idea, in theory (and short term practice). I wonder if one could do the same thing to a PC bulb. I have a dual 28w PC ballast, I wonder if I could overdrive that to 2x. That would be a very good thing for smaller tanks.

What about blowouts? The glass and pins on a bulb aren't meant to get that hot for periods of time, this may have a scary side effect,not to mention possibly blowing up the ballast.


Thanks for you questions and comments. Another long one...sorry.

There are several reasons why I used T8s instead of T12s. It is true that T12s are more availble than T8s at Home Depot. However in the construction business, T8s is practically the defacto standard. So, finding T8s is just a quick trip to a lighting store. Most stores don't give you any problems if you look like you know what you are doing :) BTW, you can use a T8 ballast to drive a T12 lamp. Most T12 lamps may not last as long because they are not design to be used with instant start -- but they will light. If you use lamps that are manufactured to be ISable, they should work fine.

T8s. They are more efficient (lumens/watt). Tthey are more environmentally friendly (less packaging, less materials used and etc). They are easier to direct intense lighting to a specific area -- less diffusion, like MH. Electronic ballasts are cheaper and easier to obtain for the T8 format. Put it this way, a 2x175W is as bright as 2x80W NOs....I just save myself 170Ws. Of course, I don't have the "heating" capabilities of the MH and the glitter lines.

End caps: The $3 endcaps that I have are rated for 600V @ 600W. The overdrive NOs are ~180V@80W -- so we are electrically safe. As for thermal, I don't think they will melt. 60 deg C water can be safely transport through PVC -- so, it should be a problem for the endcaps. My DIY reflector (white aluminum flashing) is touching the lamps and they are luke warm. You can use waterproof caps...but I think they are made from the same material...PVC (maybe hi temp PVC...I don't know). This is one of the reasons why I wanted to limit the overdrive to would be a bit risky. In comparison, I have a 55W PC on another tank. And the PCs are much hotter than the OVRNO (overdrive NO). I can't touch my PCs for more than a second.

Lamp life: Well, they should be good for a year. I have seen any black ends on my tubes...yet. I have been using them for about three months now. At $3.50 CAD per tube, I don't mind replacing them every six months. Ballast life...should be okay too. The ballast is designed to drive 110W (or 4 lamps) and the heat dissipated from the ballast is a luke warm. Nothing smells funny, acts funny or sounds funny. No sparks. Perfectly...silent.

The Waiver:
I really didn't want to say it...but I also didn't want a lawsuit either. Basically, I feel it is safe and it is something worth pursuing for a DIY reefer (otherwise...I won't have posted it). Under the "for those who dare to try" section, you will notice that we start at 1x drive first. Run it for a while. Make sure the temperature of the ballast and tube are not too hot. The ballast is engineered to drive 1 tube (i.e. the other three tubes are blown). Then...try 2x. then 3x and finally 4x. You'll find that the 3x and 4x are starting to hit the diminishing returns mark.

The shorter tubes: can use them in series. The instant start mechanism should have enough oomth to strike both tubes. If not, you can try one won't burn it out. The T8 ballast is design to light 24", 36" and 48" T8s.

I understand your concerns. It sounds scary, but I am sure it will work. Most electronic ballasts should work -- besure its a F32T8 X 4 type (you'll know, they are the second cheapest kind).

Hope that helps.

- Victor.
OK.. I love DIY, and am interested in trying this. I just want to verify a few things and add a few questions. I am by no means an electrical wizz, but I have a basic understanding of it. When it comes to lummens and wattage, and color spectrum I am lost.

1) you are taking a 30 watt bulb and driving it to 80 watts? Is the only advantage here that you are increasing the lummens? would it not be just as effective to run 4*30 watts?

2) what end caps did you use?

3) what are the overdrive ratings at 2* and 3*?

4) If you are puting out the same lumens as a mh, why do you not get the same ripple effect?



Bulb exploding ?

Okay...I guess it could happen. But the chances are...probably not. You have a higher chance of a HID (MH, MV, LPS) of blowing up since their operating temperature is much higher. I guess what I am say is that it is not that hot...not enough to boil water, crack glass...or the center brace for that matter.

The pins or electrodes blowing up...well, I guess that could happen too...eventually. It is no different from what Icecap does :) Most lamps are design to run for 10000 to 20000 hours. Most of the lifetime is reduced due to damaging effects of starting. This is where Icecap's special starting technique reduces the damaging effects. Since I am using a cheap ballast, we are going to see some damaged -- but this is expected for this type of ballast. Even if they last a year, at $3.50 CAD....I would not care. If it was a $20 actinic...okay...a little more costly.

Overdriving PCs ? can try. I am doing that already for my 55W.... If you are interested in some cheap PC ballasts, you can check out for details. Also, if you buy a ballast that is design to drive two PCs, but you only use one of the outputs....some ballasts will automatically overdrive the PC (by 20% to 40% the nominal output)

Why Do this (80W vs 4x30W)?

Well...why ? That is a pretty good question. Some corals require high intensity levels to thrive...something like sps or a fuji yellow leather. The light coming out of 4x30W is diffused over a larger area than a single 80W. Hence, 80W will create high light spots that allow some demanding corals to grow...while 4x30W would create an even lit reef.

The second reason is reflector design. It would be hard to design a compact refector that would redirect most of the light generated by 4x30W. A fairly optimum specular refector is in the shape of a M. You would need 4 reflectors for 4x30...while 80W would only need one. You could use the expensive URI tubes with internal reflectors....but if you could afford those...then why are you still using NO ? Why not MH ? Imagine trying to fit 6 to 8 reflectors under a 90 would be a mess :) But...good question.

End caps...Leviton Fluorescent Lampholder.

2X and 3x.
I believe 2x gives you 50W and 3x gives you 65W.

Ripple effect: You can only get the ripple effect if the light is directed at the water in one direction -- in other words, a point source. The fluorescent tube is closer to a line you would not see it. Too bad though....

Hope that helps.
- Victor.
Instead of an ICECAP VHO, why not use an Advance VHO ballast? You can pick them up at most electrical suppliers for $60. The Advance will drive two 110W VHOs. I don't see how cost can be an issue here.

The F32T8 bulbs are getting more common, but finding aquarium specific bulbs will be interesting. Not to mention F32 T8 are 36" and not the more common 48", although HD and Lowes are now carrying F40T8 bulbs with 5000K. Most F32T8 bulbs I see are 4200K. Yuck!

I've experimented with electronic ballasts. Tying the outputs together can lead to very noisy RF generation--all over the TV, radio.

Tube Sizes ?

F40T8 are 60"
F32T8 are 48" -- the common one.
F25T8 are 36"
F17T8 are 24"


F40T12 are 48"
F30T12 are 36"

Confusing eh ? 6500K is commonly available for F32T8s (GE, Sylvania and etc). Other "aquarium" colours are avaliable from Zoomed and Hagen.

Why not VHO ?
Problem...if I use 110W for VHO and get the same intensity with 80W OVRNO, I would rather use the OVRNO (environmentally friendly). Where does the extra power go....heat. Plus...VHO tubes are not $3.50 CAD....more like $30--$40. Also, VHO tubes are fatter...harder to control the lighting. But...again it is a lower risk lighitng solution.

Okay...the $60 VHO ballast. I looked it up and they are magnetic...lower effiency and low ballast factor (i.e. VHOs are designed to accept 110W of light power from the ballast...but the ballast delivers something lower. Typically a ballast factor of 0.85 is typical. So, the VHO ballast would only deliver 94W to your 110W VHO). If I wanted VHO...I would just get a setup from Hellolights (less hassle). Good point...just...I am having more fun with this OVRNO... :)

RFI (RF interference):
Hmm...gotta check it out. Most of appliances (TV, radio and such) are working as they usually do. Maybe, I need to place it near the reef for it to disturb it. Depending on the ballast design, RFI can be a problem..or not. However...if you shield it properly (ie place a metal foil or tube around the RF emitter -- which are usually the wires between the ballast and the tubes), then you should stop most of the RFI. Excelent point.....

I hope I am not shoving this down people's throat :) I have heard of many people asking if it is possible to overdrive NO without a Icecap. I am just posting in response. Personally, I enjoying doing stuff like this. I could always go out to the LFS and buy an Icecap ... but I think this is more fun.

Hope that helps.

- Victor.
Seems to me the main reason to do 1 4X overdriven NO rather than 4 bulbs not overdriven is the space in the hood required to hold them. IF you want to put 300W over a 55 for example, it is impossible to put 10 NOs above it, but it is possible to put 3 overdriven NOs.

thanks for the post very interesting.
Reefburnaby, some people may think you are pushing it down their throats, but i don't think so. Its kinda like the tv.. you don't like what your watching.. don't watch it... if you don't like what your reading.. don't read it. Besides this is a forum for posting ideas etc. I don't think you have to worry about it :)
BTW I find this thread to be extremely interesting, and full of information that i didn't understand before. I look forward to hearing more people come up with questions for you. I am almost convinced to try it no anyway.
Yeah, I'm overdriving 2x36" NO's with 40 watts each. Not near the scale you're talking about, but a dramatic difference none the less. I'll be doing the same, really soon with the new 135gal tank I just bought. Let's see.....I have a pair of electronic HO ballasts designed to run 4x48" bulbs each...... that's, like, 360 watts.......each. I could overdrive in pairs, 2 bulbs per ballast, and get the exact same output as VHO. All for the grand whopping total of, the bulbs, endcaps, and wire. WOOHOO!!!!

I just rigged a pair of electronic Advance ballasts in on my 36" bulbs. HO ballasts, running in the neighborhood of 90 watts each. Screw LOA's, these things rock! Nice, clean, blue, and cheap! I'll just have to wait and see what the lifespan is. They should be fine for a year as far as color goes, so the overall lifespan should be no problem. I thought these ballasts ran 4x48", but they are only for 2x48".....ah well. They are working flawlessly so far.


Holly cow...90W on 36"....

Glad to see that they worked out. Relatively, how bright do you think your lights are compared to MH or PC ?

- Victor.
Well, they're really bright compared to normal! It isn't quite painful to look at, but you can feel your pupils closing up really tight. I am getting a slight ripple effect now, too. Kinda looks like halides. Very cool stuff.:cool:

Is the reason you went with the 36 inch 30watts .v. the 48 inch 40 watts due to effeciency. Or would the 40 watt bulbs be just as efficent, but hotter?
The 40 gal tank is 36" long, so 48" wouldn't fit. I also had a pair of Ho ballasts sitting in the garage unused. These are for "24-96 inches total length". The way the schematic showed, I insulated the yellow outputs, and ran one end of the bulb with red, the other with blue, to configure the ballast for one bulb. It is rated to push 90 watts to 96" total length. Under 72" total length, the power factor is greater than 85%, as well. So, I have a pair of 36" bulbs, one actinic, one50/50, running in theory at 90 watts each. They are very warm to the touch, and the ballasts are running pretty warm. Nothing is terribly uncomfortably hot. I can hold my hand on the bulbs for several seconds before it gets too hot. I'm rather pleased so far. I'll just have to let time do its thing to see how the bulbs last.


I guess we have a bit of confusion here. I am using F32T8s..which are 4 feet long and 1 inch in diameter.

There is another tube called F30T12. These are three foot long tubes and 1.5 inches in diameter. The key is T12 vs T8.

T8s are a bit more efficient than T12. Yes, you can overdrive F40T12, but this method may shorten the lifetime of the tube (reduce the life by 20%). So, a tube that has designed to last 10000 hours, would be reduce to 8000 hours or so. These cheaper ballasts use a starting technique called instant start. There are tubes, such as F32T8, that are designed to take the stress of instant start.

I think I stated why I chose T8s over T12 in the previous posts. This overdrive technique can be used with T12.

As Imapler pointed out, you can use a HO ballast to overdrive an NO.

- Victor.
I just wanted to thank reefburnaby for this overdriving idea. I tried it about 3 weeks ago, and love it. I can't get over the difference in the corals etc. I currently am only running 2 overdriven 4* a 6500 and an actinic. I plan on doing the same with 2 more bulbs. The one thing i did try that i saw mentioned somewhere is to put aluminum tape on the top side of the bulb. I wish i had a camera to show it, but it seems to make a huge difference in the penetration. I have the two bulbs approx 1-1.5 inches off the water, and i get a ripple effect similar to halides with just the two bulbs.
Can't wait to try 2 more.
Thanks again. Got any other great ideas?