OK, I've had a question about the 3 wpg on the El Natural tanks. This is the average. Currently, I have one that is technically running at 4.3 wpg - a 65 w Coralife over the 15 gal. Others are probably around 2.0 - 2.5 wpg. BUT, I have floating plants, and while I try to keep them thinned to the point that there is some continual movement from surface flow, so there are no permanent shady spots, I'm often remiss with this. So, I'll bet the water column really isn't getting the full shot of light it could. Its VERY difficult to calculate "WPG", given all the types of fixtures, the quality of reflectors, etc. I also have 26 w over a 10 gal, but because its an AH Supply kit, it really looks MUCH brighter than another 10 I have which runs (technically) 28 watts. There is no comparison. Next time, I'll get the AH Supply kit with the great reflectors, too. I cheaped out and got the 2x13w one (rather than the 36 w w/the spiffy reflector) and put it into an existing strip light housing. I put foil tape into the existing housing to reflect better, but its not the lovely parabolic reflectors AH sells.
OK, just thought I'd head off any questions about the 3 wpg. With all the floating plants (Salvinia auriculata, Frogbit, and some dregs of Duckweed) I'm sure the actual light penetration is much less.
I have not had problems with things getting leggy - if anything, stuff in the tank with the big lighting upgrade is doing very well. The a. reineckii (Red Temple Plant) is such a hot pink/purple underneath that its beginning to look too garish for the rest of the tank. Internode length is still between 1" and 1.25", it seems tighter since the upgrade.
The one plant I'm having trouble with is Didiplis diandra (Water hedge). The old growth is blanching. New growth is a nice light green, but the older growth does not look good. I don't think its LACK of light, since when I trim it and replant, the growing tips, even now "shorter" show the same thing. I think its starved for nutrients. But, it was exhibiting this behavior to a lesser extent before the lighting upgrade. H. costata in this tank is looking beautiful, so I might replace the diandra with more H. costata.
Also in the 10 gal with the 2x13w kit, I've got some Hemianthus callictroides that is growing at a snails pace. It looks healthy, but each small piece I planted (a stem w/ 3-4 leaves each) has maybe put out one new leaf in 6 weeks. Its growing, but OH, so slowly. I'm going to wait with this, because I hope that once fully settled in, it will pick up speed like the glosso did.
-Jane |