Is It Slime/velvet Disease??

Velvet is reasonably easy to diagnose. When it's dark turn all the lights out and shine a torch on the fish. If they have a goldish sheen it's velvet in which case you need a medication that treats whitespot.
If they still look grey, it could be costia, and since that is another parasitic infection, you'd need the same treatment as for whitespot and velvet.

You can change meds faster than 4 days if you do a big water change to remove a lot of myxazin then run some carbon to adsorb the rest. But don't forget to remove the carbon before adding the second med!

Yes you can continue the myxazin. I did several consecutive courses of the similar eSHa 2000 when my last but one betta had fin rot.

The Juwel pads will be fine so long as they haven't been used before. If they have, they could be full and not remove the myxazin. I keep a box of carbon in the cupboard, a cheap one like Wilkinsons sell. And a piece of net fabric to make a sort of bag out of. If you ever get any, carbon needs washing well before it goes in the tank.

Hi Sue,

Me again...hopefully you're still talking to me? 
On reading Mervyn's thread, it occurs to me that perhaps I should keep a first aid for fishies in my cupboard... or would the things I need go out of date too quickly?  What do you recommend I should have?  What do you mean by carbon? Is it in powder form? You said you could get it from Wilkinsons, if that's right I could get my son to get a box and send it to me in my next 'Red Cross Parcel'.  There is always something I need from the UK that I can't get here....or haven't found out where.  Hopefully of course, I won't need any meds but you can bet that if I do, it will be on a Sunday or a bank holiday when everywhere is shut!  They are notorious here for having what they call 'le pont' or bridge.  This is when a bank holiday (which is always held on the actual day it falls, rather than always being a Monday like the UK) falls perhaps on a Thursday of one week with another falling on the Tuesday of the next week, so they take off the entire period between the two days as well!!!  That's ok, if you realise in time, otherwise you can get a surprise when you go shopping....and NOWHERE is open!  May is a particularly bad/good (depending on your outlook) time as the whole month is littered with bank holiday days!

Anyway, it was just a thought as I would guess if you have a problem you need to get on to it pretty quickly to give the fishies best chance of recovery.
Thanks Sue.

Resa