[BkD]

i might buy a 55w ah supply kit for a standard size(30"Lx12"Wx18"H) 29g tank. with that fixture i'll only have about 1.8 wpg. will the rotala and ludwigia species still have their red colors under that amount of light?

 

[eklikewhoa]

Most likely not.

 

[Wasserpest]

Depends a bit on the exact species. For example R. indica/rotundifolia won't have a problem with that light, L. repens neither, but if you are talking more demanding species it might be borderline.

Also, the red color of plants doesn't only come from light levels. It has to do with Nitrate levels (the lower, the redder) and Micros (more iron - more red).

Using a pink grow light brings out red hues really well too. :icon_wink