I just bought a corkscrew vallisneria http://www.liveaquaria.com/product/prod ... catid=1624

and it continues to melt a bit more day by day, just like disapears at night, and turns like a slimy brown colour...
I have 2.4 WPG and flourite gravel, and use flourish, and flourish excel, and flourish iron. not that big of a deal, just wanna know :P

how long have you had them? In my experience most of the leaves that were on the plants in the store died off but they continued to shoot out new plants which grew normally. I also have jungle vals in my 30gal hex which get so tall (roughly 3' in length) they get algae on them and the tops die off which is fine, otherwise they'd block out the light from new sprouts.

stop using the excell, and clip the plants back, any dead or even remotely dead looking leaves need to be clipped off, do a partial water change, and try not to disturb the root structure, the problem with excel is that it can actually burn the leaves, causing fast rot, ie the slimy green kind that looks like the plant is melting, bring up your co2 level a little bit, and use root spikes nutrient/fertilizer spikes. push them in near the base the plant, this should cull the root decay, and speed up the recovery time for the plants.

Hope this helps,
Brandon

excel has carbon in it. but im making a DIY c02 system at the moment. lol chemicals suck

It wouldn't be lack of CO2 thats causing your problem....definately get rid of any carbon product when growing plants.

LOL blowing in the fish tank, huh? Is that the new DIY CO2 solution? I'm going to see if i can hire a couple kids from the neighborhood to do it...put them on 2 hour shifts maybe...