Help: plants keep turning yellow and rusty

[janesc2003]

Hi, everyone:

I've got some problems with live plants. They used to very healthy when I got them. Now some plants turn yellow and some others become rusty. And none of them are growing more within three months though they're fast-growing plants. My tank is a 65G one. It used to a salt water tank and comes with a coralife lighting (four long bulbs, 96W, 10,000k). I'm using only two bulbs and let them on for 10-12 hours a day. I just found out this morning that I'm getting a little bit of algea on the glass now. Does it mean there's too much light?
I went to the pet store this morning and was told the tank water parameters might be ok as all my fish are doing fine. It just need plant food/nutrition for the plants to grow. Is it true? Or I have to get both plant food and the testing kit? I now have a KH testing kit only. Where can I get these stuff for a better price?
And is it normal that guppies eat plants? I saw some of my guppies (especially pregnant females) eating my plants. Sorry I don't know the names of my plants except java moss.
Any advice would be greatly appreciated.

[Captured Moments]

I don't think guppies eat plants unless they are decaying and they hungry and they peck on plant debris maybe. 2 bulbs @ 96 watts should be enough to grow most plants but it's not really the right spectrum @ 10000K. Plants prefer around 6700 K spectrum.
Looks like your plants are dying because they are starving and something is deficient. Probably fertilizers but it can also be deficient in carbon source. Presume your tank is 4 ft. so 2 bulbs would put you around 1.5 watts per gallon, low-medium light level I would guess.
Your tank would most likely benefit from the addition of some fertilizers (Micro and Macro on occasion) as well as some carbon source such as injecting Co2, putting Flourish Excel (Seachem brand) or a medical supply product Metricide 14 which can be used instead of Flourish Excel.
10-12 hrs of light is perhaps too long a photoperiod. I would try reducing it to 8-10 hrs of light instead.. that would help with the algae as well.
Algae on the glass does not allways translate to too much light. It is more of something to do with a balance between the plant health given the growing conditions (light, ferts, carbon source - your 3 elements essentially).