# DIY Lighting Hydrophonics grow light or Xenon HID



## dogtemple (Aug 9, 2011)

Hi

i'm new to all this but have been doing a shed load of reading for weeks and weeks. ive got to the point where my research needs a helping hand.

I am building up a planted tank, it is going to be almost entirely DIY for the sake of cost plus it allows me to do what i want and try other approaches.

I am building an optiwhite tank, 60x60x30cm. really like the idea of a shallow tank, plus the glass thickness i have is limiting me to nothing much taller than 30cm. looking at getting lily pipes and co2 diffusers hand made locally and going to have a crack at Diatomaceous earth (cat litter, dont hate me...) as part of the substrate after a long chat with a bonsai shop owner about acadama.

The part i need some opinions on is the lighting. I have a hydrophonic grow light, 125watt 6500k - very bright and looks like this









and a few sets of xenon HID kits for cars, 35watt 6500k, they are very bright and run off a 12v supply.

i suspect the grow light would possibly push out too much light but do the job better perhaps? but also it would consume more power. the HIDs are bright and use less power (im trying to keep costs down so this is a big plus!)


these are my options since the grow light i got from a boot fair for £3 and the HIDs i already have. im not looking to buy any luminaires etc.

any hanging system and reflectors will be made out of tubing and sheet metal.



so thats my little back story, would anyone with the knowledge be able to shed some light (no pun intended) on the pitfalls of my choices here please?

i have not found a huge amount on HIDs, they work on the same principle as metal hallides so in theory i think should be ok.

hydrophonic lights just bring back loads on cannabis plants which is not what im into. but theyre CFL lights so i guess this could be a goer? yet theyre probably too much in the watts per gallon but then this is allegedly outdated! i need a little help on this one please!


I want to try and be forward thinking as much as my budget will allow on this and not resign myself to giving up and just buying something that will do the job.


some thoughts would be appreciated!

cheers!

Andy


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## Hoppy (Dec 24, 2005)

That monster bulb doesn't impress me at all. It is just 5 normal power compact fluorescent bulbs packaged as a single bulb, with a ballast to match. The big problem is that all of the light emitted by the inside half of each of the 5 "sub-bulbs" is wasted - it can't get out to be reflected into the tank. And, that loss is in addition to the restrike loss normal to PC bulbs. Much more effective would be fewer normal power compact fluorescent bulbs arranged in a row or two rows, so a good reflector could reflect the light from the back of each out to the tank. 

I know nothing about the other bulbs, except that I have read nothing to make me want to try them. Have you looked at building your own LED light?


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## dogtemple (Aug 9, 2011)

yeah i considered LED but i'm finding that they're a bit hit and miss on the PAR front. but i havn't looked in depth at it in all honesty, could be another option. but the factory made units are very pricey, thats partly why i have not gone down that route yet.

ok so the grow light, you're essentially saying its inefficient. it kicks out a lot of light but has you say the middle part is wasted.


were there any reasons you didnt go into looking further at xenons then? i'm getting the impression you've not read anything good about them?

i'm looking for a valid reason why not - otherwise i'll give it a crack.


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## dogtemple (Aug 9, 2011)

also whats the general aim with light distribution and fall off?

is it to be as uniform as possible? with soft shadows? hard shadows?

i know this sort of thing is subjective but i would like to know. 

i guess uniform with soft shadows would be the best set up, to eliminate dark areas etc


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