Just an observation, but you know how you said your angels had cotton mouth, is there any chance that the loach caught it. Its hard to make out from the photo but there may be something there or it may just be blurring.
He has reappeared this morning and seems to be looking for food doesn't have the strength to keep looking. He wants to eat - how can I get it to him?
The co2 is on a contoller with a probe in the tank. It's fed in via a bubble counter then dispersed in the flow from the internal filter. My understanding is that live plants produce co2 when it's dark so wouldn't this affect the ph within a 24 hr cycle anyway?
if you cna catch some of the snails put them in the hospital if not i found this that might help i didnt know a bout teh shrimps Clown loaches are carnivores and only eat vegetables to complement their diet. It is therefore recommended that they are given food that reflects this. To get your clown loaches to grow, optimal feeding 3-5 times a day is recommended. (They still grow slowly). Their diet should contain a variety of foods, and can include almost any carnivorous food. A good base may be shrimps, different sinking wafers, different frozen foods, and as they grow older, fish slices. Clown loaches can make a clicking sound, and they will do this when they are content. Therefore you will soon find out what is your loaches' favourite food by them clicking when they receive it. Like most other fish, clown loaches might need some time to accept new foods, however once they do it might become a favourite. Clown loaches are one of the few fishes that eat and like snails, and can therefore be of good use in snail control.
so i would try live blood worm ( moving food might get his attention) frozen blood worm dafnai and i have no ide aif flake food is good for them or not