New plants on a downward slope

[hawkeye01]

4 days ago I planted about 40 new plants in my 75g tank. I am new to the plant game. So I could use a little help. The plants I have are all low light
Im using a 67 watt All-glass light with a 10,000k & 5,000k bulb. Along with a 130 watt Aqualight using 50/50 6,700k bulbs. Eco-Complete as my substrate.

Well my problem is some of the plants are starting to turn brown. Mostly my Jungle Vallisneria, and my Pennywort. I now that I should wait about 4 weeks before adding fertilizer. But also I dont want my plants to slowly die off. What should I do?

[Blinky]

Sorry to hear you're having a hard time, hopefully we can help :)
The first thing I notice is you're using a 50/50 bulb, which means the plants really aren't getting the full 130W - actinics aren't really useful to plants so AFAIK they're really only getting useful light from half of that bulb, which means there's really 1.75WPG over your 75g. I'd replace the 50/50 bulb with something between 5000 - 10 000K as soon as you can, it will give the tank a lot more useable light.
I'm not sure why someone would recommend waiting an entire month before fertilizing, that's too long IMO. It's a good idea to let them settle in a bit so they're growing and will use the ferts, but a month without food is too long and they probably won't do well.
Without much info, it's hard to tell exactly what's happening, but I'm guessing the plants are starving for nutrients and possibly suffering from a lack of light. If they've been in the tank more than a week, I'd start adding ferts and see if they perk up.

[hawkeye01]

Thats what I was thinking too. But I wanted to get everyones opinion. I know that the 50/50 light is more for salt water. I ordered the light on the internet looking for the cheapest price, in doing so I failed to double check what bulbs where in the fixture. So instead of paying $116 for the light I needed I grabed this one for $10 cheaper. Now I have to spend $60 to get the right bulbs in it. But I will pick up come fertilizer tomorrow. Thanks for the help.

[johnnyxxl]

go to lowes or another home and garden and buy the bulbs there much cheaper and same thing I think they are the growth lights like 4 bucks a piece for 4 foot bulb

[hawkeye01]

I can get a bulb for a PC at lowes. Its a coralife aqualight

[Blinky]

I'd call first, you may be able to find PC bulbs there, but I believe Johnnyxxl is talking about standard fluorescents. The only PCs my HD seems to sell are either the little 13W ones or spirals, but maybe you'll luck out :)
Check out sites like hellolights.com too, there are some places you can buy online for very reasonable prices. There are often bulbs avaialable on ebay as well.

[ergo sum]

I wouldn't worry about the lights at this point I would worry about the water chemistry. CO2 KH, etc. Also some people say that vals die back and then start to grow.
Here is a bit about that.
http://www.aquariacentral.com/forums/showthread.php?t=47328

As for the pennywort is that hydrocotyle? It too might need to adjust a bit. Here is a bit about that.
http://www.thekrib.com/Plants/Plants/pennywort.html

I don't think it actually grows well under low light.