Sick Betta Please Help!

[Newbetta269]

Hello all i am after advice for helping my sick Betta,

I've had him about six months in a 21 litre tank shared with 4 neons.

Water quality has been good for a while however last check showed PH was 6.

I have some photos but I'm not sure how to post.

Betta hides away all day or stays at bottom of tank. He is covered in white/silver substance that is getting worse. It doesn't look like cotton wool.

Any advice appreciated as i try to upload some photos.

 

[eaglesaquarium]

Seems to me you have too many fish in that little tank.  That would be fine for the betta alone, but the neons need more space than that.
 
Your nitrate is likely very high, causing a pH crash and the betta isn't suited for low pH like that.
 
 
 
I'd suggest water changes... lots of them and soon.  Start with a 25% change today.  Tomorrow another 25%.  Then a 50% the next and the day after that.  Meanwhile you need to get another tank for the neons or rehome them.  Don't do that until you get the water quality where it belongs...
 
0 ppm ammonia
0 ppm nitrite
<40 ppm nitrate
 
 
The pH should be very close to what your tap water is after sitting for 24 hours.

 

[NickAu]

Maintenance:
Before your Betta became ill how often did you perform a water change?
What percentage of water did you change?
Do you vacuum the substrate or just dip out water?
What additives do you use?
 
Housing:
How many gallons is your tank?
Does it have a filter?
Does it have a heater?
What temperature is your tank?
Does your tank have an air stone or other type of aeration?
Does your Betta have tank mates? What kind?
 
Water Parameters:
What are your water parameters? Please give exact numbers. If tested by pet store please get exact numbers. "Fine" or "Safe" won't help us help you.

Ammonia:
Nitrite:
Nitrate:
pH:

 

[Newbetta269]

Thanks for the advice.

I'll do a water change and post parameters as soon as I finish work.

Water changes are 25% once a week using a gravel hoover. I don't use any additives.

The tank has a heater and filter but no air stone. It's 4.6 gallons. I have the betta, 4 neon tetras and 2 catfish.

I've attached some photos.

 

[eaglesaquarium]

That's a lot of fish in that small tank.

 

[Newbetta269]

Checked my parameters.
NO3-10
NO2-0
GH >21
KH - 10
pH - 6,4
CL2-0

Going do do 25% water change now.