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Re: CP for 90 gallon plant tank

>I am looking to light my 90 gallon tank with wooden canopy (48 wide).  I am
>pretty sure I am going to go with retrofit compact fluorescents.  I am
>hoping to fill the tank with a lot of freshwater plants and fish.  I dont
>plan on getting into the heavy supplementing and CO2 stuff.  There is also a
>chance I may make the tank a brackish tank, but probably not salt.  The
>three major systems I am looking at are the JBJ retrofit dx-rdx 48 with 4
>65watt bulbs (total 260watts),  the AH Supplies retrofit 4 96 watt bulb
>(total 384 watts) bright kit (the beast), or the Hellolights PC/CF 46.5 4
>96 watt bulbs retro kit (total 384 watts).

Sounds like *serious* lighting. Probably more than you need for some of 
those combinations. I doubt you'll need to exceed 300 watts over a 90g tank 
to be successful, and without CO2 and proper fertilization you might 
actually find it difficult to keep your tank in good shape at those 
lighting levels. The more light you use the more nutrients the plants will 

>         The JBJ comes with 7100K blue bulbs and 10,000K or 6500K bulbs 
> depending on
>whom you buy it from.  The cheapest place I found was 239.99 without
>         The AH supplies costs 214.99 without shipping and bulbs.  There 
> bulbs are
>32.99-36.99 each.  So I can get any type of bulb I want with that.
>         The Hellolights is the most expensive at 365.99 and they let you 
> chose any
>combination of bulb you want.

You'll probably like the 6500K bulbs best, but remember that there is 
always some personal preference in lighting colors. I would stay away from 
any colored (blue/red/etc.) bulbs though. I personally would not want to 
use a 10000K bulb on a plant tank, but I know some people who do and are 
happy with it. The best way to judge this is to go to a good LFS and look 
at operating fixtures with relatively new bulbs (color spectrums can shift 
over time in lights) and decide which one looks best to you over a similar 
tank setup to what you are planning.

>         So my questions are:  Which system is the best and why?  Is this 
> too much
>light for a 90 gallon?  Should I go smaller?  Which types of bulbs and what
>combination do you recommend?  If the back of the canopy is open, would that
>much lighting need a cooling fan?

Wow, sounds like a dangerous flame-starter kind of question there with all 
the brands you mention ;-)

I think 384 watts is probably too much light for a 90g tank, especially if 
you aren't planning on using CO2 and regular fertilization. I'd look for 
somewhere in the 200-300 watt range for lighting, and when you consider 
available bulb sizes this will probably mean a range of from 2 96 watt 
bulbs through maybe 4 55w bulbs. Find out what will fit in your tank AND 
give you the lighting you want. I personally would look for 5500K to 6700K 
bulbs for a planted tank, which is what I use on all of my tanks. I find 
that range is a good white (not yellowish) light that looks good on the 
fish and plants in the tanks. Those bulbs also tend to be cheaper than the 
more exotic 10000K+ bulbs that tend to be aimed more at the reefer market.

For the fixture, if you already have a hood and can get a retrofit kit from 
AH Supply that will fit AND provide enough light, then that will probably 
be your best option in terms of price and appearance. I've heard both very 
good and very bad things about JBJ recently and since I don't have any 
experience with them myself I'm not in a good position to talk about 
pros/cons with them.

You *may* need a small fan or two for cooling but it depends on the hood. I 
use small fans on my tanks mainly to keep the hoods from making "hot 
plastic smell" when they heat up. Some of my fixtures are full open frame 
and just use convection cooling. I'd try the lights without a fan first and 
only add one if you need to. If you don't need the fan you can avoid the 
cost, installation time, and noise that the fan will involve.

If you use a standard hood made for your tank, get a hood with two parallel 
(or four if they are half-length) light bars. This way you can fit more 
lighting over the tank with less work. IMHO, the best configuration for 
your tank would be four 55w PCF lights, for a total of 210 watts. I think 
you'll find it easier to use the 55w bulbs that are around 24" long rather 
than the 96w bulbs that are around 36" long. It's easier to install the 
bulbs when they will fit end-to-end over your tank without being at funny 
angles to the sides of the tank.



Waveform Technology
UNIX Systems Administrator