I'm a beginner with a 58 gallon tank, 196 Watts of CF lighting, CO2 injection and Flourite substrate. The plants I have seem pretty happy and are growing well. The one exception, I think, is the vallisneria. They've put out daughters and I can see some impressive roots on one near the glass, but the new growth doesn't look right. The leaves are spotted with a fairly regular pattern of dark red/brown "bars". The new leaves also have a reddish hue to them. The older growth that floated on the surface had to be trimmed away because of algae (hair, I think).

I'm using Tropica Mastergrow at the recommended dosage. Doing 1/3 water changes weakly and have a KH of 4-5. The GH is only 3-4, but TDS is 250 ppm.

Any ideas?

You didn't mention your dosing method. Do you use the EI method and dose all of the nutrients listed in it?

There is a species of vallisneria that has reddish leaves, so it may be possible that you have that one. PlantGeek.net - Vallisneria spiralis

I'm not using the EI. Right now all I do is add 30 ml of Tropica Mastergrow after the water change. Tropica doesn't say what's in it other than Iron and other essentials with no nitrates or phosphates.

My nitrate is about 20 ppm via Red Sea test kit. I don't have a phosphate test kit. Ditto iron.

I know it's hard to answer without knowing exactly what I'm dosing. I was hoping maybe someone had seen something similar before.

BTW, the vallisneria in question are not the red variety. They were quite green when I got them. The original growth remains green. It's just the new growth that is reddish.

You have a lot of light for that size tank, so I strongly suggest you use the EI method of dosing, and dose all of the plant nutrients. Nitrate and phosphate, as well as iron test kits are notoriously innacurate, unless you verify their accuracy by callibrating them with samples of water having known amounts of nitrate, etc. in them. With the EI method you don't need to test the water for nutrients.

You also need CO2 with that much light. And, for that big a tank it will be much cheaper and more sitisfactory if you go to pressurized CO2, using a drop checker to determine how much you are putting into the water so you can adjust it correctly.

Back to the vals: As I remember, new growth on the vals I have had, especially on the non-spiral ones, has been golden to reddish color until they get to be a few inches long. Maybe I am confusing it with another plant, but I'm pretty sure I have seen that.