The fish does show a gold sheen in some of the pictures but that could be his normal colour. If you had a picture of when you first got him, you could compare the colour from that image to the present day pictures. If they both show him with a gold sheen it is probably colour.
If the glass shrimp were kept in a tank with fish that had velvet then they might have introduced the disease. However, if the glass shrimp were in their own tank at the petshop, then it is unlikely to be velvet.
Velvet has to be introduced into an aquarium with contaminated fish, plants, water or other types of aquatic organisms (snails, shrimp). Because nothing else has been added, except the shrimp, it is unlikely to be velvet.
The glass shrimp should be fine at 86F (30C) so that would be one way to make sure it is not velvet. Raise the temperature to 30C and keep it there for 2 weeks and it will kill any protozoan parasites in the water or on the fish.
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The cloudy water is caused by excess food and fish waste not being broken down by the filter. Do a 75% water change and gravel clean the substrate each day for a couple of weeks. If there is ammonia or even low levels of nitrite in the water, it can irritate the fish's skin and cause them to rub on objects in the tank.
If you take a glass full of tank water to the local petshop, they should be able to test the ammonia for you. Some shops charge a small fee to cover the cost of their test kits. If the shop does test your water, write the results down (in numbers) at the time they do the test.
If you have dry paper strip test kits, then try to find a liquid test kit when you get the ammonia one or when the others run out. The liquid test kits are more accurate.
When you do buy test kits check the expiry date on them and try to keep the kits cool and dry. I kept mine in a plastic container with a lid and put them in the fridge.
*NB* make sure children and animals can't get the test kits because they contain poisonous chemicals.
*NB* make sure you rinse the test phials under the tap after doing water tests, and wash your hands with warm soapy water.
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What sort of filter do you have and how do you clean it?
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If you have a light on the tank, you could try adding some floating plants like Water Sprite (Ceratopteris thalictroides/ cornuta) to the tank. Floating plants use nutrients and help keep the water cleaner for longer. They also provide shelter for the fish and shrimp and can help reduce stress.