From the pictures it looks like blood in the eye, unfortunately there really isn't much that can be done as far as intervention for healing. All you can do is ensure that the wound doesn't become infected with the use of AQ salt as prescribed by Sakura.
Until such a time as you can obtain some AQ salt it is imperative to ensure you undertake 100% water changes once a day. I highly recommend stress coat to aid in healing, which also doubles as a water conditioner.
My recommendation for a great basic Betta setup would be:
- 2.5g tank (minimum)
- Substrate (not sharp)
- Silk plants and decorations if desired (DIY is also possible – mugs, jugs, PVC pipe, terracotta pots [not sharp and no holes where lil dude can get stuck])
- Heater (depending how big of a tank you go, will depend on wattage. The General rule is 1w per g.)
- Internal suction thermometre
- Hikari Betta Food, AQ Salt and Epsom Salt (although we wont be using epsom salts at this time, it is good to have on hand for the possible future)
A tank under 5g is difficult to cycle, so a filter won’t be necessary. With that sort of setup I believe you will be able to undertake a 50% water change with a 100% water change every other day. But I get confused and it may be best to get the tank you prefer, then consult us again for your best course of action (whether that be cycling or a water change schedule)
Oops, sorry I missed the 2nd page of this thread. Only just saw it when I finished writing this. *derp*
My water change trick is to get a clean mug - no soap residue. Boil the mug if your unsure. Once the mug is ready, place it near the surface, without any water in it and angle the base into the water, once the lil dude comes up to breath push the mug under and it will suck water into the mug along with the Betta.
This eliminates the need to run around the tank with a net, and it also serves as his temporary home whilst the main tank is being cleaned. Word of warning though, place a cloth over the top of the mug to prevent light stress and also jumping - my little guy jumped from a tuppaware container and I spent the next 2 minutes searching the area until I found him! That was a panickfest.
PS. No soap or detergents or anything when cleaning tank. Just hot water :)