Overview
My fish started developing whit spots on their tail fins. At first it was 1 or 2 spots on about half of them, and now there seems to be a cluster on one of my snakes. The spots seem to appear in the little nodes in their fins, doesn't look random. I do have driftwood which has developed white fungus, but I have read here that this is normal and not harmful.

Please see my video below:

https://youtu.be/wHuDpk7DIFA


Questionnaire
1. Please explain the problems with your fish.
I have only had the fish for 10 days, so everything is new to them. However I noticed the spots on day 2, they may have always been there, I didn't notice because I didn't turn on the lights until the second day.


2. Symptoms
Other than the white spots, I noticed that their poop has a little bit of white.


3. Medication
Nothing

4. Tank size and ages, numbers and sizes of fish.
55 gallon tank, 6 discus, 4 - 12 months of age.

5. Water change regime (What percentage and how often).
I am chaning 20 gallons twice a week.

6. How long has tank been running?
Bare bottom, been running for decades. I did have an ich breakout in December. I cleaned out the tank and cycled from January to March 16th when I brought the fish home.

7. Do you age your water? If you do for how long and what is the ph swing.
I age my water for 24 hours. ph goes from 7.8 - 8.2

8. Parameters and water source;
I use straight municipal water, and my water is hard. Temp is 86F, ammonia 0.25ppm, nitrite is 0ppm, nitrates are 20ppm.


9. Any new fish, plants or inverts added recently.
No

10. Please tell us what you feed your fish and how often.
I feed the sellers beef heart mix, and Hans Discus fish flakes.

Thanks for your help.