Cycling Situation!

Hi guys,
I was previously cycling my tank, but decided to start over because I believe the ammonia was too high and it was killing all the good bacteria off. It was about 6.0ppm and a strange, oily film was forming around the sides and top. The ammonia would raise back this high even when I would do larger water changes. It went on like this for about 3 months.

Setting up this new tank, I kept some of the old water. (About 5%?) And I didn't scrub the bottom, (only the sides, because they were oily). I didn't rinse my filter cartridge either, because I assumed it had to have some good stuff in there. This time around, I also added imagitarium's biological booster (only "bacteria in a bottle" my pet store had).

Can my axolotl be in the tank in these early stages of cycling when the ammonia, nitrites, nitrates are low? (Reason I'm asking, is because she's been in this tub for a few months, and not only is it hard for me to lift to change the water, but I miss seeing her swim in her tank! it's not worth it if it could harm her, however.) I was thinking the bacteria I've used might hurt her if she suddenly goes from just dechlorinated water to this tank water, but I honestly don't know. She's currently in a big storage tub with about 5-10 gals of dechlorinated water I've been changing out.
Also, should I ever add any more of the bio booster? The bottle doesn't say anything about it, and I can't find that information online. If so, when?

Sorry for the long message, and please correct me if I'm doing anything horribly wrong! I'm very new to the whole cycling thing. :dizzy:

Avoid putting the axolotl in the tank, just to be careful. Is there any substrate in the tank? Substrate and the filter will hold the most bacteria. What brand of bacteria are you using? I'll see if I can find anything. If it's easier for you (and you don't already do this) have 2 tubs you can alternate her between so you don't have to do a lot of lifting. Just put new water in one tub, put her in (after temp checking) then drain the other tub with a siphon.

I'm using the imagitarium brand of bacteria, with no substrate is in the tank. Also, even after changing almost all the water and cleaning the sides, there is still a strange oily film that I had to skim off the top with a net and I'm not really sure why.