I read somewhere that light or white colored substrate will give you better lighting because it reflects more light compared to a dark back covered bottom? It does seem to make sense. But how much better is it? Does it effect plant growth any?

For instance...
Would 20 gallon tank, white substrate, and 1 wpg be much different (light and plant growth wise) then a 20 gallon, black substrate and 1 wpg?

Is this something to take into consideration when picking gravel/sand/substrate? It seems most of the flourite type stuff comes in dark colors.

Hope to hear others opinions and experiences one this!

In my experience, any benefit you get from having light substrate will be outweighed by a few other factors.

First off, if you have a very light substrate then you'll be able to tell VERY quickly when it gets a bit of algae, mulm, or fish poo that is common in a planted tank. It will get gunky looking very quickly and won't look too hot.

Secondly, I have noticed that fish, when given a darker environment as far as backgrounds and substrates, tend to hold better color. A white background or white substrate washes out the colors of the fish dramatically. You may be able to avoid this if you have a lot of plant cover, but it is something to keep in mind.

Thirdly, a white substrate is very unforgiving when it comes to evenness and layout. It silloettes your foreground and draws attention to any flaws in the "horizon" created by the surface of the substrate.

Check out http://showcase.aquatic-gardeners.org/2006.cgi
You'll see that many of the BEST tanks go with darker or more natural colored substrates, mostly for the reasons I've outlined.

Anyone else have opinions?

my opinion is......that i agree with you 100 %
white sand looks good for the first minute after you clean it......

Well JenThePlantGeek, thats very interesting. I do infact have a tank with light colored sand and that mulmy stuff did stand out!

But I was asking light vs. dark just purely about the benifits of the reflective light, not so much about looks. Still, though, very informative! Thank you!

Once the plants grow a bit, the substrate largely disappears anyway, so if there is an advantage it doesn't last long.

I would say no effect on plant growth.

The relfection would be minimal. The plants are USED to getting light from above not below...so that might confuse growth. PLUS...and in my opinion the most important thing...I think the whole issue is mute since it's really just what our eye preceives. It's not actually brighter in the tank...it's just that there is something White to see in the tank. a white ROCK has 0 WPG associated with it. The reclection at or towards a plant would be so minimal that 0 wpg is the realistic measure.
And like Hoppy said. Once any plants grow on it, the whole experiment is over. The only thing that I think might actually work like you said is if the substrait were as reflective (effective at it) as the reflector in your light hood. Like tons of crome reflective beads that would blind you as you walked by. But again I wonder if that would just confuse the growth of the plant?

Very interesting... thanks! Confuse plant growth? I can see it now...

One of us should contact NASA to have them set up a planted tank in the International Space Station. Then we could eliminate the effect of gravity and see just how a confused plant grows!

I've often wondered about how to get extra light into a tank - I have a little hexagon tank that has a dome in the base of it which sits over a bulb built into the base - just a large christmas light type bulb so it makes little difference aside from making the tank into a good nightlight, but I wonder if you could do "spotlight domes" or something like that in bigger tanks.

Has anyone tried spotlights aimed into the tank from the sides?

And the thought of ultra-reflective gravel, like chrome beads is, well, kinda cool... Not sure how practical it could be, but the "modern look" might be very appealing.

http://science.msfc.nasa.gov/headlin...ast10may_1.htm
http://earthobservatory.nasa.gov/Lib..._breathe3.html

And there are some on the ISS, but as usual with some of these sites, can't find any info on it...