Lethargic or dying Betta

Question
Hi Chris,
We adopted a tank some 18 months ago with a plec some neons and a weatherloach. We recently bought 3 female Bettas and one male, who is magnificent. (soon after we introduced 5 tetras and a tiny black shark.) He was slightly larger and much more impressive than the other males, which may suggest he is a little older?
We have had them two weeks now, and he has chesed the girls around non stop. I think the girls are prime for mating as they have vertical stips under their colours. The other day we lost some neons, and now I think we may loose him. He just droops around the plants, and I caught him lying in the gravel earlier today and I was really worried about him, Now he is just hiding and I think he is dying. He glorious fins are looking suddenly tatty and I need to know if there is anything we can do, or what may have caused his sudden turn? The water is fine as I have had it tested, it's 26 oc and clear. He has not been nipped whilst we have been present but no fish seem to be chasing him. Any ideas please?

Answer
Chris has been unable to answer your question due to computer failure. You can ask another volunteer expert or post your question on the forum at our sister site About.com in the freshwater aquarium section. There are many knowledgable members there that should be able to help. The website address for the forum is;

http://freshaquarium.about.com/mpboards.htm

Thank You for your patience. Chris should be available again in 2 weeks.