Miss Dib Dabs
Loony.
You need to keep doing daily water changes. There shouldn't be any ammonia or nirtrIte readings. 
If you think your filter is to blame I'd suggest making sure it isn't clogged up in any way, as it can and does happen. Regular checks of filters are something you should do anyway.
I small ehiem ecco (external) would filter a tank that size well. I use them on two of my tanks and they do a good job. Can't remember what I paid tho, sorry. Most externals aren't cheap for sure. There are internals which are ok, like fluval makes.
Hugs,
P.
If you think your filter is to blame I'd suggest making sure it isn't clogged up in any way, as it can and does happen. Regular checks of filters are something you should do anyway.
I small ehiem ecco (external) would filter a tank that size well. I use them on two of my tanks and they do a good job. Can't remember what I paid tho, sorry. Most externals aren't cheap for sure. There are internals which are ok, like fluval makes.
Hugs,
P.
