As this mod went through a few revisions, I thought I'd take the opportunity to recap the "final version" in one post.

Legal Disclaimer: This mod is documented for the sole purpose of sharing what I've done. No warranty is expressed or implied. If you choose to do this yourself, you do it at your own risk.

Summary
Installation of a 70W Metal Halide retrofit kit into the stock Nano Cube 12G DX hood. This mod also includes improving the cooling of the hood, as well as providing cooling of the water against the MH lighting.
The reasons for using certain components or configurations will not be explained in this post (it is in the preceeding posts of this thread). This is a simple step-by-step of what I did.

Objecives
Get MH into a Nano Cube 12G, while maitaining the stock look (no drilling the tank, no pumping water out to a sump, no opening of the front flap, etc). The aquarium must remain practically useful to keep a reef (e.g. stable water temperatures, tank inhabitants must be able to thrive not just survive).

Testing environment
This mod was created/modified over a period of 4 weeks, in the Spring of 2005. Daily photo period was 8 hours with room (ambient) temperature ranging from 65 (overnight) to 80 (when the house A/C kicks in). Daily water temperature ranged from 79.2 (when the heater kicks in) to 81.2 (at the end of the photo period).

Equipment
Items needed:
$150 - 70W MH retro off AquaBuys (site sponsor!).
$10 - The kit comes with a 10k bulb. I'd recommend getting a higher spectrum bulb, such as the Aqualine 13k option for $10 more, or the 20k option for $12 more. If you do not get a higher (at least 13k) spectrum, you should figure out how to provide actinic supplementation for the health of your corals.
$10 - 4 fans that provide more cooling power than the stock ones. I got these.
$15 - 1 scroll fan (aka "blower").
$21 - 3 variable voltage adapters.
$5 - Quick-setting high-temperature epoxy (rated to hold at temperatures up to 300F), from Home Depot.
-----
$211 (not including any taxes or shipping)

Additional items used:
* Nano Cube 12G DX
* Screwdriver set
* Wire cutter/stripper
* Wire nuts (you can also solder, use heat shrink, or any other method to join wires together)
* Electrical tape
* Longer screws to mount the thicker fans
* Dremel (you can also use jigsaw or other devices to cut 2 vents in the hood)

Time to complete the mod
Done in 2 sittings (recommended, to give the epoxy more time to cure to full strength) it can easily be done in one period of 3 hours followed by a second period of 2 hours.

Complexity or skills required
It's pretty simple (I am not very handy ).
Besides following simple written instructions (e.g. "connect blue wire to black wire"), using the dremel to cut two rear vents (doesn't even have to be cut in a straight line, but it'll look nicer ) is the hardest part.

This post has been edited by artarmon42: Dec 3 2005, 09:27 PM

The first phase should take up to 3 hours. If you're relatively handy, it can take as little as 45 minutes.

1) Detach the hood from the Nano Cube.
2) Remove the splashguard, and the proceed to gut it. Remove everything, including the reflector, fans, and wires for the stock PC lighting.

3) Using the high-temperature epoxy, glue the MH kit's DE Bulb Socket directly to the hood.

4) Follow the MH installation/wiring instructions that came with the retro kit. Don't forget to install the bulb and the UV glass shield!
5) In place of the stock fans, install 2 of the new fans. These fans need to be positioned so that it will blow air OUT THE TOP of the hood.
6) Using the wire-stripper, wire nuts and electrical tape, connect the 2 rear fans to one variable voltage adapter. Set the voltage at 7.5V.
7) Using the screw-holes that held the stock reflector in place, install 2 of the new fans. These fans should be positioned to blow air TOWARDS the splashguard.
8 ) Using the wire-stripper, wire nuts and electrical tape, connect the 2 front fans to another variable voltage adapter. Set the voltage at 7.5V.
9) You can be extra-neat in dressing the wires by tying them together (to streamline airflow) and threadding it through the rear holes that used to channel the stock PC lighting wires. When done, the hood should look something like this:

10) Test the fans by plugging in each voltage adapter.
11) After verifying that the UV glass is in place, test the MH by plugging in the power. NOTE: Never look directly into the light... temporary or permanent blindness can occur!
12) Power everything down, reinstall the splashguard, and then reattach the hood to the Nano Cube.
13) Phase 1 is complete.

The system is now ready for a "burn-in" test.
NOTE: Both voltage adapters (that power the 4 fans) must remain ON at all times. Insufficient cooling (especially after MH has turned off, but while it is still hot) will warp/melt the splashguard.

As instructed in the MH retro kit, the tank must be acclimatized to MH over a period of days. Start with a 2-hour photo period, and increase it by half-an-hour for the next 4 days, then increase it by an hour per day until the desired photo duration is reached (e.g. it should take 9 days to get to a full 8 hour photo period).
NOTE: Improper acclimatization will damage/kill tank inhabitants.

Until Phase 2 of this mod is complete, keep the front (feeding) flap open. This will avoid a rapid rise in tank temperature, as there is insufficient cooling of the tank until the second phase is done.


Running the system for the first 2 hours, there should be noticeably warm air being exhausted out the rear/top vents. Closely monitor the system: feeling the temperature of the top of the hood, looking for signs of warp on the splashguard, making sure the water temperature doesn't go up more than 3 degrees in the first 3 hours. Increase the voltage settings on one or both of the adapters additional hood cooling effects.
NOTE: Lowering the voltage settings is not recommended as insufficient cooling will warp/melt the splashguard over time.

The second phase should take up to 2 hours. If you're relatively handy, it can take as little as 30 minutes.

After the completion of Phase 1, wait at least 24 hours prior to starting this phase. Time must be given for the epoxy (holding the MH to the hood) to cure.

1) Detach the hood from the Nano Cube.
2) Remove the splashguard, and inspect the components for any problems. Ensure that wires are still held by wire nuts and electrical tape as originally intended. The epoxy should be cured and the MH unit should be securely bonded to the hood. Reinstall the splashguard.
3) Using a Dremel (with cutting attachment), create 2 vents in the rear of the hood.

4) Install the scroll fan into one of the slots, using the epoxy to attach it and to seal off any air gaps. NOTE: While the epoxy will solidify in 5-10 minutes, it will take at least 24 hours to cure to full strength. During this time, avoid rough handling of the hood and/or scroll fan.

5) Using the wire-stripper, wire nuts and electrical tape, connect the scroll fans to one variable voltage adapter. Set the voltage at 6V. This is the only variable voltage adapter that can be synchronized to the MH (both on, both off). NOTE: Running this scroll fan 24 hours is not recommended as it will increase water evaporation and salt creep without any additional benefit.
6) Reattach the hood to the Nano Cube.

7) Phase 2, and the whole MH-mod is complete.

The system now has a way to vent the air gap between the splashguard and the water surface. This provides better cooling to the tank, as well as better oxygen exchange. The front (feeding) flap may now be closed.

With both phases complete, the MH should now have very minor impact to the water temperature. During a full 8 hour photo period, my water temperature rises by 1-1.5 degrees only.

The scroll fan cooling does cause some water evaporation. My 12G DX requires 1/10 of a quart of top-off every day (although with that small amount, the top-off could be done once every few days).

I will be happy to answer questions people might have.
Thanks for your interest!

EDIT: Check out .13 Fathom's version. His placement/tilt of the fan plus forward air-gap vents is a great modification to this step.

This post has been edited by artarmon42: Feb 13 2006, 11:30 PM

Artarmon42

Thank you for the wonderful detail of your mod.

I plan on saving this and using this as my bible for the upgrade.

Great work.

Cheers

Hey if you don't mind. I'll toss this into a pdf and put it up on a server so people can download it.

Let me know.

Sure, no problem!

This has got to be one of the most clear and consise threads I have read. I appreciate the effort you put into this experiment and for documenting it so thoroughly. Thanks to you I am confident that I too can get the benefits of MH in my nano.


I ordered everything as you indicated and I'm currently bidding on the 70w MH retro kit. I can't wait to get this all together and see it in action.

I wanted to thank you also for this. This is what these forums are designed for


THANK YOU


One question... are you having or do you expect any issues w/ salt/water creep into the connections (wire nut) and into the fans?

Nope, the 12G DX is very (and you could say "too") air tight.

The light chamber (inside the hood) is very well protected by the splashguard with rubber seal. I have found no trace of moisture anywhere inside, not even on the wires coming out.

The other connections (e.g. wire nuts) are outside of my tank in the back, and I've found no trace of moisture there either.

Since the addition of the rear vent/fan, I haven't noticed anymore condensation on the splashguard.

In my opinion, the most likely "problem" (with the Nano Cube design, not just my mods) is the rusting of the splashguard screws. So I check those religiously, and am pleased to report that everything appears fine so far.

There is a little salt creep just at the water line (as the water level drops, some salt is left behind at the previous level). Easily taken care off (wipe it back into the water) as part of the weekly maintenance/water-change.

I've love to get your feedback on how this mod works for you!
Let us know!

One more question... I too had been looking at purchasing the MH on ebay... BUT I dont have the NC dx. I just have the dual fan model. It sounds like my lack of a good splashguard and gasket might make this a little more challenging than I had thought....what are you thoughts?

Do you get the same shimmering on the sand bed as you do w/ any MH you see in a LFS?

The 70MH definitely gives you the shimmering (I run bare bottom).


I actually think this mod is possible in the old model.

The only catch is that I don't recall the screw-points in the hood... just need to make sure that you can screw in at least 2 fans.
You will have the run the fans at full speed, if there are only 2 fans vs. the 4 that I used.

If you don't have the screw-points, that may not be too bad either...

I think a better way to go (regardless of whether you have the screw-points or not) is to use wider (e.g. 80mm or even 120mm) fans for more CFM. You'd have to figure out how to mount those fans... I imagine epoxy some spacers (to create space on either side of the fan) to the hood, and then epoxy fans onto those spacers. Definitely do-able, but it'll be semi-permanent with the epoxy so make sure measure everything out first

I think you'll want to shoot for 40+ CFM in that area to adequately cool the MH.

I'm thinking that the hardest part of this entire project is going to be obtaining the 70watt retro kit. I'm currently fighting for it on ebay. It appears the guy only puts one kit up for bid a week and lets us duke it out for it. Perhaps I'll try contacting him somehow and asking him if I could purchase the item in some other way. If not, then it looks like I might have to bid quite a bit for it in the end.

Hey Bobbozr2,

I just order my 70 MH Kit from Lamp DR. He's a site sponser to boot.

http://www.nano-reef.com/forums/showthread...?threadid=54013

70W Electronic Mh Retrokit:

Includes:

BALLAST- Aromat 5EU new style ballast.
LAMP- Choice of Ushio 10k, Astralux 14k, and BLV 20K.
REFLECTOR- 9inc x 7 inc chrome relfector.
SOCKET- HQI ceramic socket.
CORDS- 6ft. 16 gauge socket cord, and 6ft grounded plug.

PRICE: $145.00 SHIPPED. ADD $20.00 FOR BLV 20K LAMP.

[img]http://www.nano-reef.com/forums/attachment.php?postid=470137[/img]

This is what I just bought.

btw, Bobbozr2, let it go. I know which one you are talking about. Get it from our site sponser if you don't win it. Great price and great service.

I've just been told you don't have to buy the retro kit on eBay.
http://www.aquabuys.com/miva/merchant.mvc?...Product_Count=2
It does look like they're on backorder, but at least you're not fighting other people on auction

Really any 70W retro kit should work.
But PLEASE, for your safety and those of your tank inhabitants, when dealing with DE bulbs make sure ALL light passes through UV-blocking glass. Blindness CAN occur, not to mention all the badness that can happen with UV exposure (skin cancer, death to fish/corals, etc).

On the topic of UV protection, I always thought that Ed-N's post was very cool. Hope he doesn't mind me linking it

I bought one of those testers and made sure it read ZERO all over the inside of my hood.

Thanks for the advice guys. I actually contacted him via email last night and he gave me the link to his site. I emailed him back and I'm able to get the retro kit without the bulb for $94.50 + shipping. I already have a 20k bulb so going this route has saved me more money. I'm actually glad the auction never worked out.

So he's not back-ordered and can ship right away?
Great deal Bobbozr2!

Well, he said he's getting them in tomorrow. Even if he doesn't get them until even earlier next week, at that price it sure beats what I would have paid for it the other way.

I got all my fans and variable voltage adapters today. It's all coming together. I can't wait.