pregnant blood fin tetras/ammonia

I have two pregnant blood fin tetras that came as such from LFS. One of them looks like she is going to pop (and has been this way for about 2 weeks). The other is not quite as rounded. I have had some trouble with my ammonia levels. I am doing water changes every few days to keep it below 0.25 and sometimes it shoots up to 1.0. I think this is due to my Pleco (Charlie) because he eats a lot (boy are my tank walls clean) and he's growing RAPIDLY. I notice he poops long strings frequently (I know, gross). Could this be the reason that the tetra's won't lay their eggs? I have lots of "baby hiders" in the tank just in case. I was going to get one of those little net thing to protect them when they hatch. Any advice is appreciated. Also, I have some temperature fluxuations because my heater was messed up. They don't have a heater, water temp is about 77 steady (I live in Alabama and it's hot).

All suggestions are appreciated.

Tank community:
1 pleco (Charlie, about 4 inches long)
9 black tetras
4 blood fin tetras
3 ghost shrimp
1 live plant - Amazon sword
1 piece of driftwood
everything else is fake (I know, more plants will help my ammonia not spike)

It's a 29G tank. I check the ammonia every day and have been changing water (50%) daily since the levels have been high. I even got a python to vacuum the gravel since that seems to make the most difference in getting the ammonia down. The tank has been set up for about 3.5 months. Really, all this started as the pleco started to grow. I bought him at LFS and it just said common pleco. I looked at pictures online and he looks like this: http://www.aquahobby.com/gallery/e_Common_Plecos_Hypostomus_Liposarcus.php

I was giving him a small bit of pleco wafer every day but I have dropped that back to every other day. Will my cycle catch up with this load? It was cycled before I got him and I was only changing water about once a week. Should I get another tank for some of the other fish? Consider planting more things to help absorb the ammonia?
Thanks!

I don't think I could part with him. I'll get a bigger tank for him. He has so much personality.

In the meantime, I'll keep up the water changes and reduce the bioload by moving some of the others to another tank (like the prego tetras).

It sucks but if I keep doing 40-50% with the python, I can keep it in acceptable ranges until I can get another tank. It's just annoying because I have to hook it to a hose outside, down stairs, then refill with a bucket because the water from the hose is too cold. Maybe I'll get that extender so I can reach the kitchen sink.

I wonder how large of a tank I need to get to realistically keep him. I'll post a new thread with that question. Thanks for all your help.

Update - I got a python extender at my local store, SOOOO much easier. I did frequent water changes and now I'm back under 0.25 for four days straight now. I'm keeping my eye out for a bigger tank (and saving up for it). I think Charlie is okay for now but hope to have him moved within six months. I'll keep checking ammonia every day until then. Thanks for all your help!