VHO and RO

> I've been doing some research on what type of lighting to buy.  I've see
> some set-ups for $300 with VHO lamps.  I plan on lighting a 55 gal. tank. 
> I could buy two twin shop lights for $15.  Two cool white and two warm flo.
> bulbs would run c. $6.  This would give me a decent spectrum for minimal
> cost.  

They aren't very efficient lamps, yes, they are cheap.  Were I you, I'd 
probably spend a few more dollars per tube to get some triphosphor 5,000K
CCT lamps, maybe blend in one or two "full spectrum" lamps as well.
> Is there any great advantage to HO and VHO set-ups?  The cost difference is
> huge.  Any input? 

You get about twice the light output per lamp with VHO.  I'm not sure 
that one can justify VHO cost on a 55 gallon tank, nor is 4x110 watt VHO 
luminous flux required for most aquatic plants in a 55 gallon tank.

Icecap VHO ballasts are probably the most reasonable way to go for VHO 
ballasts.  The lamps last a lot longer, and at $20 a pop, it doesn't 
take long to amortize the price of the ballast.

For your purposes, 4x normal output lamps would give you approximately 
the same amount of light as 2x VHO lamps.  I'd say that 4x normal output 
would be a lot better value for you.


> From: Ric Cooney <cooney29 at mail_idt.net>
> Date: Sat, 24 Aug 1996 18:56:33 +0000
> Subject: RO Units
> I don't understand why you dont get a DI system like the Aquarium
> Pharmaceuticals Tap Water Purifier  or Kati and Ani. They both can be
> recharged and the end cost and end purification are much greater than an
> RO unit.

Yes, the end cost of water purified by a disposable ion-exchange rig will 
be a lot higher than an RO unit, if you do reasonable things to keep the 
membrane protected.  If the water in your area is exceptionally hard, 
then you may do well to pretreat the water going into the RO unit with a 
water softener.  Otherwise, one can get supersaturation of calcium 
carbonate in the unit, and the calcium carbonate crystals grow through and 
destroy the RO membrane.

If you have really hard water, you will probably get about 20 gallons out 
of an AP deionization rig before some contaminants start to break 
through.  Phosphate and silicate are the first two off.  

What to do depends a lot on how much water you need purified, and what 
degree of purity you require.  Higher is not necessarily always better. For 
topoff water, you can use RO/DI.  For water exchanges, I'd think that you 
would need to do a total ionic reconstruction if you wanted to use 
RO/DI.  There are some products like that on the market.  I've been 
thinking pretty seriously about putting together a one or two-part 
suppliment for that purpose.

Spectrapure makes reasonable RO units and their membranes are pretty good 
as well.  I get between a 98 and 99% rejection of phosphate with their RO 
membrane, as advertized.  I've not validated the performance of other brands.