Well jpeterson, maybe we should discuss it some more before we decide on the right kind of change.
Assaye, I didn't really express myself well. I don't have any problem with the technique of cleaning out the traces of ammonia with a zeolite resin that's after the biomedia in the water path - the theory of the technique is ok. What I worry about is that people have reported the stingray to be so bad at preventing pass-through that it raises my worry that if a stingray comes with fresh zeolite that happens to be a strong-enough resin, it could effectively wipe all the ammonia out of the tank (a small tank as in this case) while the biomedia was experiencing a low exposure to needed levels of oxygen and ammonia because of pass-through (water able to get past the media without having to go through it.)
I have not owned a stingray though and am basing my thoughts on cases I've read here on TFF. I can't remember now but maybe you've run one of these Assaye? It could be that I've just been erroneously given too negative an impression about their performance.
~~waterdrop~~
I run one in my 30 litre betta tank and it works like a charm. The zeolite gave a much needed boost when I had ammonia problems and never had a problem with the water flowing through the media properly.
However, that only proves mine works and doesn't prove anything general about the make.
I think only time will tell if jpeterson's Stingray will work. It certainly wasn't responsible for the swift deaths. I would always have a back-up filter on hand but a good fishless cycle will prove once and for all whether he's got a good or bad filter.