Problems With My Plants :(

Hi Guys, I'm in need of a little help, I am running my Juwel Rio 180 with 2 T5 lights in the hood, front one for fish colour and back one to enhance plant growth, I have 1" of aquatic compost under my fine gravel, all my water conditions are good with minimal to 0 readings, a good oversized external filter and 2 heaters. I also use liquid fertilizer on occasion.
My tank was running some 3 years ago, for around 5 years and I loved my live plants, (no c02 injection), but had great success, due to house moves the tank was broken down, and my fish re-housed, now it's all set back up I am have real problems with plants, once they are in the tank the leaves thin and drop quickly, and they go very leggy, (tall and thin with only a few leaves at the top of the plant), and I just can't work out why.
I have bought from the same fish shop that i used to, as well a trying a couple of new ones and the out come is always the same! It's getting really frustrating, and I just can't work it out. I enjoy having a planted tank and would like for my plants to do well again, for the look of the tank and I believe the fish are happier with the cover they provide.
Sorry for the long ramble, but I'm all out of ideas...............Thanks in advance 

Have you replaced the bulbs? I've read that its worth changing the tubes at least once a year and some say every 6 months. Hence why I opted for LEDs. Might be worth a go...

Plants need food and light (water too of course, but that's not a concern in an an aquarium)

If you are growing only a few easy plants and/or live in an area where your water supply gets a lot of runoff from agricultural land, then I guess you could get away without feeding your plants.

Clearly, Richard W has found success here, but I'm sure you'll find his approach will work only very rarely and only if you're very fortunate.

If you look at any specialist forum, dedicated to planted aquariums, you won't find many people, if anyone, recommending you rely on only the fish poo to act as your fertiliser.

If you have gone to the time and effort and expense of adding the plants to your aquarium, why would you then go on to neglect them or just hope for the best?

Plant food doesn't have to be expensive, and it can be as simple as adding it once a week, build it into your routine, say after a weekly water change and its not an onerous task.

And, I do agree with the above recommendation to ensure your bulbs are in good condition.
Anything over a year old won't be producing anywhere near enough light.