Help identifying illness please

[Sallysophia]

Hello, I am very worried obviously- my big guy, blood parrot cross red dragon overnight presented with this white fluff. Water parameters are ok with exception of nitrates a touch higher than ideal but not off the charts. He has been healthy and never had any issues for his four years of life. He’s acting pretty normal, itchying himself on the sand and wood though, but breathing normal, swimming normal, he even ate a little bit last night (of course I scooped out uneaten food) keeping tank very clean and doing twice daily 15% water changes.
Both my clown loaches died the same night this white stuff appeared. Very sad very stressed over here.

 

[Aiken Drum]

Can you try and fill in as much of the info requested on the "unhealthy fish" sticky please.

https://www.aquariumadvice.com/forums/f17/before-posting-about-unhealthy-fish-read-this-32451.html

 

[Sallysophia]

Blood parrot cross red devil. cotton like growth
2~What are your tank parameters (ammonia, nitrites, nitrates, temp, pH)? I don’t have exacts just colours showing normal. .
3~ How large is the tank? How long has the tank been set up? 75 gal. 2 years
4~What type of filtration are you using? Please give the name and number (sponge filters two big ones and two internal filters.
5~How many fish are in the tank? What kinds of fish are they and what are their current sizes? - 12 inch fluffy guy. One two inch blue acara one 5 inch Severum
6~When is the last time you did a water change and vacuum the gravel? How often do you do this? How much water do you remove at a time? 15% vaccum every two days.
7~How long have you had the fish? If the fish is new, how did you acclimate it/them? 2 years
8~Have you added anything new to the tank--decor, new dechlorinator, new substrate, etc.? No
9~What kind of food have you been feeding your fish, have you changed their diet recently? Haven’t changed. Cichlids pellets and brine shrimp