Odd white bit on gill. Any help apppreciated :)

Hi, I've had my wild type axolotl Joannna for about a week now, shes in a 40L tank and has a diet of bloodworms, brine shrimp, and sometimes little bits like liver from the butchers to keep things interesting and I mix it alll randomly, she gets fed every 2-3 days. The temperature of the tank is normally bobbing around 20 depending on how the house gets (we're a student house). Anyway at the weekend I did a water change and fed her. Today I went to feed her again and I noticed a little patch of white on one of her gills, it dosent look like anything else is wrong with her and she ate one out of 2 bits of food i put in her tank to give her a choice today, any she dosent eat I'll remove. The tank is filtered but a pretty weak one and it has plants. I took measurements of the ammonia and nitrite and nitrates using a colour strip testing kit. The Nitrite was somewhere between white i.e. 0.0 and the first pink square which is 0.5. The ammonia coloured up in the stressed zone. I've assumed that it is this which has lead to this so I'm slowly doing a 50% water change to see if that makes things any better. I know theyre meant to be messy creatures so exactly how often should i be changing the water, is there anything else I can do about this? Thanks in advance.

I've heard a lot of different opinions on water changes, but mostly I hear about 25% weekly. If your ammonia is at high levels, that should be your first priority. High ammonia levels can easily lead to an unhealthy axie. It seems most axies tend to get white bits on their gills, but most of the time it just goes away. You also might want to include earth worms in your feeding schedule, as they are probably the most nutritious option. Do water changes, get the ammonia down, and see if problem is resolved.

While my tank was cycling I did daily 20 % water changes, plus regular spot cleaning. I tested the water regularly too until the ammonia went....boy did it take a long time!!
I found the link below really useful.

Caudata Culture Articles - Cycling

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