Compact vs. VHO, Which way do I go?

[Bill]

I have a 90gal freshwater planted aquarium (24x48x18 HxWxD). I have 5
40watt NO T-12's, disabled down to three tubes. One of my
2-tube-ballasts has gone bad. It's a complete 2-tube Coral Life
system, so the ballast looks difficult/dangerous for me to change out.
Since I've never been happy with my watt/gallon ratio, it's time to do
some thinking...

Here's a decent price on a 3 VHO system:
http://www.hellolights.com/3laaromo4lvb.html

In going from 40watt NO to 110 VHO, do the lumens change in the same
4:11 ratio? Is the 330 watts of VHO light equivalent to 330 watts of
NO light? Or am I putting out seriously more/less lumens per watt?

On the CF issue, I could go with four 65watt tubes using the DIY kit
at the same site:
http://www.hellolights.com/2xbalkit.html
It's a bit more pricy going this route. So what do I get with CF vs
VHO? Longer tube life? Less heat? More lumens per watt? I'm not
looking for space savings, I have a roomy slatted wooden hood with the
ability to install clips for any of the tubes I select.

The CF ballast indicates it can do 55 or 65 watt tubes. If I do CF,
how do these comparisons work:
200 NO watts vs 330 VHO watts vs 220(or 260) CF watts

Am I baking my plants at either of the VHO or CF configurations?

My plants are OK right now. I'd like to see them do a little better.
Fish are healthy. Algae under control. Pressurized CO2 system
running at a slow trickle.


Thanks for reading this far.
Bill.

P.S. I have access to sheet metal bending equipment. I can make my
own reflector to accomodate any tube configuration.

[Bill]

On Fri, 21 May 2004 17:16:57 GMT, nanoreef >
wrote:

>No. VHO is more efficient then NO. IIRC NO is from 40-60 Lumens/watt,
>and VHO is 75-85 lumens. Power Compact Flouro (PC) produce about
>85-90Lumens/watt. PC tubes should last 2 times longer then VHO which
>have an expected life of about 6-9mounths. PC last about 12-18 months.

Okay, so let's do some math...

I'll eliminate one of the VHO tubes to put the wattages in the same
range.

My setup options thus compare in this way:
200-watts NO vs 220-watts VHO vs 220-watts PC (my CF)
or:
200 : 330 : 220
using your ranges, the lumen ratio is:
8000-12000 : 16500-18700 : 18700-19800 (or 22100-23400 65-watt PC)

I can thus eliminate the third VHO completely. If I went with the
three VHO bulbs, the lumen count would shock my aquarium with a range
of 24750-28050. If I were to use NO tubes, I'd need 12-15 tubes to
produce that many lumens. ( I'd also need a dozen cooling fans and a
fire suppression system.)

I think the 4 55-watt bulbs should be enough for my tank. It'd be
more than double the lumens I was getting before. The lower cost over
the life of the tank for tubes is another selling points.

Thanks,
Bill.