Poorly Fish

[Gozofish]

My little gastromyzon is sick. He isn't eating and he's going pink underneath and very pale on top. Water parameters all good. All other fish fine.
I've moved him into a 10 litre hospital tank and doing daily water changes.
He got into a scuffle with false julii Cory over a spirulina flake beginning of last week and I'm wondering if he got spiked.
What can I do to help him? Are there any meds safe to use that might help him? He's my very favourite fish
I've added before and after pics

[black ghost]

It’s not really a suitable companion for most corys as it requires a very fast flow and saturated oxygen levels. The ideal setup is a river manifold tank which is ‘dirty’, ie biofilm on the glass and rocks etc. They rarely do well in your average community setup.

The pink belly sounds bacterial.

[Gozofish]

When I put higher flow in the tank he avoided it and stayed in calmer areas
I'm waiting for my surprise sewellia babies to grow in other tank as my intention is to set up a tank just for the hill streams.

[black ghost]

When I put higher flow in the tank he avoided it and stayed in calmer areas

because it was Ill I’d guess.

[Gozofish]

Nope he just preferred calmer areas. At that point was eating well, good colour, even came to front when he saw me coming to feed them in morning

[plankton]

It does sound bacterial so you'll need an anti-bacterial med.
Is there algae and fresh veg for him?

[Gozofish]

Plankton he has an algae covered anubius and some courgette. Loach forum on Facebook advised esha 2000 which they said is mild can be used full dose for loaches which I'm going to try 1st.
He's hanging in there and moving around a little so hope the meds arrive tomorrow in time

[black ghost]

They eat biofilm rather than algae. Don’t clean the glass (except the front glass obviously, for viewing reasons).