Pelvic fins melting away

[FishLover]

Hi,
I'm having trouble with three of my 11 discus having their pelvic fins tip melting away. No idea why. The fins start to become almost transparent/white at the tip, then just melt away. Fish are eating fine.

I started using Discus Buffer few weeks back. Since it is a phosphate based product, I'm wondering if that's the cause.

Another thing I did was put some plants bulbs there. These were the dry ones that I got from the LFS. I thought that may not carry anything nasty. It turns out some of these bulbs were having some kind of fugus going on after in the water for few days. I took these out today.

I first tried the salt treatment. Nothing changed. I'm now using Melfex(?) starting yesterday. Only the tips were gone at this time.

I'm wonder if I'm on the right track or not. Was it because of high level of phosphate? Or was it because of the fugus that I brought in with the plant bulbs? I really hate to give up Discus Buffer since it made my life so much easier in terms of W/C. I use 1 tsp per 10 g of water for the new water. I also use soemthing to dechlro it before pumping the water into the tank.

Current details of my tannk
125 g
11 3" discus
3 cory
4 otto
PH 6.89, dose not change much
No ammo
No nitrate
light on 12 hours per day(2 96 w bulbs)
lightly planted
Some driftwood
phosphate must be high because I'm using Discus Buffer
Not much of algae problem because it is still under control
36W UV runs 24x7(I turned it off today because of the treatment)
temp 86-89F (due to the season change, our room temp goes up and down about 6 to 8 F per day, that cause the tank temp change from day to day)
40% W/C per week
2 - 3 feedings /day, Frozen BW and flake food

Sorry for the long note. I'm trying to give out information as much as I can so I can get some help sooner.

[G-1000]

Hi There,

As far as using discus buffer goes - you need to be very careful as it can cause pH burn.

For example if you previously had tank pH of 8, now it is 6 then your tank is now 100 times more acidic than previously (pH is an exponential scale). Thus it will obviously stress your fish to do this.

So pH is possible.

Also - there may have been a minor change in pH which reduced the immune status of the fish - leading to increased susceptability of the fish to the fungus from the plant. This is less likely.

So what was the pH before and after using the discus buffer ?

G

[FishLover]

Hi G-1000,

Hmmm... The PH was 7.3 or so before that. I was using peat to lower the PH before I started with Discus Buffer. I lowered the tank water with Discus Buffer in few days to 6.89. In the process, I added some Discus Buffer directly into the tank. Some of them might caught some strong acid at that time.

Thanks for the reply