This is a major problem with so-called plant or aquarium tubes. They are high in the red (and usually blue too) as photosynthesis is driven by red and blue light (the red is slightly more important for this), but reds and blue which are primary colours on many fish are "highlighted." Some people like this, I personally do not; the purplish, reddish or bluish hue these tubes (depends upon the phosphors/colour wavelengths) give the aquarium does not render colours of fish, plants and decor true. The other problem with such tubes is they are generally less intense light than the "daylight" tubes that are high in red and blue but also include green in the mix.
I have been trying out LED lately, and a couple weeks back had a look at two so-called plant LEDs in a local fish store. The fellow kindly placed them over a planted 20g tank so I could see what they looked like. One had white lights and a row of red down the middle, with separate switches. The white alone was not bad, but very cold. As soon as the red was switched on with the white, the black gravel in the tank became purple, very remarkably so. Mixing colours for good aquarium light is not easy.
I recently bought a new All Glass light for one of my tanks, and like the others I purchased several years ago for other tanks, the tubes in it are red/purplish. I expected this and they went to the recycling. The Aqueon Floramax also do the same. This is common with plant or aqua named tubes.
I am assuming you have just the one tube, so here I would recommend a tube with high red, blue and green. Tubes with a Kelvin (this is the measurement of the colour temperature of light) between 5000K and 7000K, or a CRI (colour rendering index) between 80 to 100, tend to work best, both for plant photosynthesis and overall appearance. Unfortunately there is more to this, as the phosphors themselves affect the light, so all full spectrum or 6500K tubes are not the same; manufacturers can make these differently. One might expect the full spectrum Aqueon tube that Steven linked to be it, but this is not a good tube. I acquired one (two actually) only a couple weeks ago, and found them very disappointing, and they too will be going to the recycler very soon. It is hard to explain just what this tube does, but it is very "blah" light. The greens of the plants took on a sort of greyish hue. It is easy for me to see these various hues, as with 8 planted tanks in the room, changing to a different tube over one of them can be compared with the others.
There are two tubes I would recommend here. One is the ZooMed UltraSun (6500K) and the other is the Hagen Life-Glo (6700K). I have both and they are nearly identical. The Life-Glo is probably the best single tube light for a freshwater planted aquarium. These are also stronger intensity that other tubes of the same size/wattage.
Byron.
/www.aqueonproducts.com/products/fullspectrum-daylight-t8-fluorescent-lamp.htm
