Whats wrong with my gecko?

Question
QUESTION: Ok I have 2 questions. First is, I was wondering if I gave you the info on my geckos if you could tell me what is wrong with them. Or at least attempt to. I have read your other postings, so I am going to answer the questions that you asked them. I got my first gecko last December and had her for about 4 months. She was SUPER tiny (baby wise) and was very energetic and grew very quickly and ate rather well. Towards the end of March I purchased another one from the same pet store and made sure to quarantine them for 3 months. My oldest had a 10 gallon and the smallest had a 5 1/2 gallon. Both had moist hide boxes and day and night lights. I kept (and still keep) the tanks at an average of 89-90 degrees during the day and 85-87 degrees during the night. Well about a month and a half after moving them into a bigger tank (I believe it is a 29 gallon) so I could fit both of their favorite pieces in the same tank, my oldest one became uninterested in crickets (I fed the little one meal worms and the big one live crickets). So I decided to try meal worms for both. And they both ate them. After a while of that my oldest stopped eating completely. I didn't really notice (because I left meal worms in a container 24/7 and they were getting eaten) until I looked closely and noticed her tail was thinning. Well I got SUPER paranoid after reading all the stuff out there on the "crippling disease". I decided to take both of them to another pet store that someone I know and trust with my geckos and gecko info worked. On the way in my oldest one pooped and it was EXTREMELY runny and kind of a off white/yellowish color with what looked like a sac in it. The girl popped it and there was even more liquid in there. Unfortunately, I wasn't able to retreive it before it hardened. But she said that it didn't look like GC (my oldest) had the "crippling disease" because she looked at her belly (she too has numerous geckos). But she said it did look like both had worms because you could just start to see their ribs. She told me to get safe guard, which is a horse dewormer (fenbendazole) and I can't remember the dosage she told me to give to them (which was my other question). I have tried force feeding GC but the last time I tried she threw it up. She has become very lethargic and slow moving, sleeping all the time, except for when I take her out, she gets all of her energy back. I have sand as a substrate and as soon as I can, I am changing it to reptile carpet. I do not have a under tank heater on the new tank, but I did on GC's old one (don't know if that has too much to do with it). I do have a little bottle top cap full of calcium powder. Like I said I have tried feed her live crickets first, then meal worms, and then waxworms to try and beef her up. Now she won't eat anything. I haven't recently cleaned out the "toilet" area of their cage, but I know I need to. And I did say I have sand as a substrate, but it is calci-sand. Don't know if that would make a difference. I don't have anyway to pay for a fecal on him or a vet visit as I am a student and am barely making it by with what I am making. Again, I've bought the de-wormer and I don't have their weights currently, but I plan on going home and getting them and then giving them to you. I would greatly appreciate all the advice you can give me. Sorry my letter is so long, but these two are my babies and it would absolutely kill me if anything happened to them, especially knowing there had to be SOMETHING that I could've done.

ANSWER: Hello Elyse,
Thanks for all of that information on your tank setup.  It sounds like you have everything setup correctly.
The main thing is the sand.  The calcisand is dangerous & can cause impaction.  Whether or not this is the problem, I don't know.
I don't recommend loose substrates for a couple of reasons.  The main one is impaction, & the other one is it harbours too much bacteria that can make your reptile sick.  Essentially, the live in their toilet.  Even if you scoop the feces material out, inevitably some liquid most likely was left behind or other traces as well.  They can accidentally ingest any oocysts which will make them sick.
The Panacur is very safe.  I will help you deworm them with the proper weight, in grams.  
Are you getting extra oral fluid into them both?  You may need to manually open the mouth & get foods into GC since she is not doing very well & has lost fat reserves in her tail.

Tracie

---------- FOLLOW-UP ----------

QUESTION: Thanks again Tracie! I actually went home and changed the substrate this afternoon after I got off from work. I now have a reptile carpet on the floor of the tank. I'm trying to get extra fluid into them. I've been trying to give them warm baths and kind of massage them as they are just sitting there. I know I am going to have to force feed GC because that is the only way she will eat anything. I've gotten some ideas from other questions, such as the baby food with a pinch of ReptiCal in it. I might also try bathing them in warm Pedialyte, because I've heard of doing that too. But thanks again for everything!

Answer
Hello Elyse,

Great you got the substrate changed out now.  That should help quite a bit I think to keep it cleaner & reduce bacteria too.  
I know it is not fun having to assist feed GC, but she is getting too thin.  Yes, the repcal calcium should be put in with the babyfood to balance the phosphorus levels out.
The pedialyte is helpful too.  Make sure you bathe them in the clear pedialyte & not the colored type.  
Keep me posted on her.  

Tracie