Loaches Online Forum

They are very expensive, which is why I've not bought livestock from them before and the shops I have used have been good. Just an issue with the suppliers, I reckon, and I'll be steering clear now.

I'm struggling to find infofigures on how best to set up the UV for this issue - I don't suppose you have any, do you? I've not got one yet because I'm not sure on what size to get. The weather loach with the slight problems appears to have a bit of a kink in his spine now which I am not at all thrilled to see, but I've got to at least try this idea while the others are all still robustly healthy (at least externally). No joy on a vet so I'll be dissecting the worst affected gold barb myself on Friday.

Read about which brands are available to you.
Mostly, whatever watts and flow rates are suggested for your tank size that will kill free floating algae will also kill most microorganisms that are in the water.
Generally I see 2 basic set ups:
Slower flow and more watts for larger organisms like parasites.
Faster flow or lower watts OK for single celled things like green water algae and bacteria.

I have no idea how resistant to UV are Mycobacteria. When in doubt I would go with more watts and slower flow over the UV bulb but a large enough unit that the whole aquarium volume of water is passed through the unit fairly frequently.