75 Gallon Tank Brown Spots on Gourami

What are these spots on my Blue Gourami? He's a few years old amd has had some scaly build upon his fins. Now thesebrown spots have showed up in recent weeks. What do I do? (Ignore the algae spots)

 

It looks like his scales are missing and he has a large section of his tail missing. Is there another fish in the tank that could be bullying him? What are your water paramters?

 

My gourmai had pink abrasions like this recently as well. I had to do water changes more frequently, and dosed with SeaChem Stress Guard. It does look like some of his tail is missing, is he alone in the aquarium? What sort of decorations is in it? What's your water parameters?

 

Thank you both for your answers. After posting this, I did get a closer look at him. He's definitely missing scales... Looks like hes been in a war. He generally hides in this upright tree stump looking thing. He's been out in the open for the past couple weeks... So that's strange too. I also changed my canister filter recently (the old one keep leaking)... Maybe it's too strong and I should get a spray bar. I'm due for a water change, so will do that. I'll also test the water and report back. I always had stress coat after a water change, so I'll do that as well. Thanks again.

 

After changing water

Ph is roughly 7.2
Ammonia and nitrates are 0
Nitrates are 10-20

Tankmates are red tail shark, another type of shark (not sure what), Congo tetra... Some snails and clown plecos
Here's a photo of the whole setup

 

A couple things that could be a problem- gourami like planted tanks (even fake plants help) to reduce stress. The sharks are known to be aggressive and will nip fish. The tetras can also be aggressive if not kept in a school. I would do daily water changes and add some StressCoat if possible to see if this helps. I would also add tall plants in case this is a case of aggression and keep an eye on tankmates to see if one or more can be caught being a bully. Tall plants will help give the gourami a place to hide and feel more comfortable.

 

More hiding spaces would be a good idea for sure! Gourami's like tall plants, and coverage, it took me awhile to figure out how to make my aquarium the best space for him. I added a pirate ship, which he goes in a lot, and more natural and fake plants. He felt more comfortable not being completely out in the open. Unlike my other fish, who just swim all over the tank without a care in the world.