Ill Marble Sailfin Plec :(

[Kay20uk]

Tank size: 90L - 20 (UK) Gallons
pH: 7.6
ammonia: 0
nitrite: 0
nitrate: 5
kH:
gH:
tank temp: 25.0
Water was recently tested at our local aquatic center.

Fish Symptoms (include full description including lesion, color, location, fish behavior): Covered in a white slime type substance (has decreased over the past week or so).. Has light patches all over him, looks similar to when they get stressed out. Behaving as normal, swimming around plenty and eating algae .

Volume and Frequency of water changes: 10L of R.O water once a week or so.

Chemical Additives or Media in your tank: None.

Tank inhabitants: 1 ruby shark, 1 marble sailfin plec, 1 gold ram, 5 baby platys, 1 baby gourami.

Recent additions to your tank (living or decoration): Slate (but he was ill before we added this).

Exposure to chemicals: None.

Digital photo (include if possible):

 

[WILDER]

White slime on fish can be parasites, ph shock, bacterial.

Does the fish show any of these signs.
Flicking and rubbing.
Darting, erratic swimming.
laboured breathing, or gasping.
Sores or red pin prick marks on the fish.

Has your ph changed.
What do his gills look like.

Is he a new addition to the tank.
Also I would advise buying some liquid test kits of your own. As the lfs don't always tell you the truth.

Research the plec for tank size.
The ruby shark really needs a 40 gallon tank.

 

[Kay20uk]

I had some decoration in the tank and it was growing white slime on it, like this -

then i noticed the plec was starting get ill and covered in the slime so i removed the decorations and he seems to be slightly better since then. The slime is not growing anywhere else that i can see since I've removed those decorations.

The plec is not showing any of those signs, he seems fine apart from that slime on him and his colour being a bit off. The pH has always remained the same since the tank was set up about 3 months ago. The test results on my first post where my results, we just have lfs test it to double check.
All the fish in the tank are babies at the moment, and i am fully prepared for them to outgrow the tank.. we have a 55 gallon tank downstairs for when this time comes ..

EDIT - Sorry about the picture size, i don't know how to fix it ..

 

[WILDER]

Keep preforming water changes.

If the fish gets worse get back to the board.
Good Luck.