I purchased a 65 gallon used aquarium. It had been used for saltwater fish. It is pretty nasty. I hosed everything out. The pump has some worm looking things all throughout it. They feel like rocks. I am going to use the aquarium for freshwater fish. What is the best way to clean it up?
I'd say white vinegar will help loosen the white "wormy" things...& a no soap fine-ish "scrubby" pad too. Repeat as needed, it may take a few tries.
Your Rena (2?) filter looks to need new coarse & medium sponges, some bio bits...maybe a filter pad, it's kind of optional. I don't think I'd bother with the carbon pouch, it's likely shot (carbon is very optional). Don't forget to clean the impellor, gently! Crud has likely dried on it, again white vinegar & be gentle...ish.
You can carefully razor blade the tank after a vinegar soak. Do not blade into the silicone!! There might be some etching of the glass from mineral deposits. Don't panic, fill it with water & see if they're noticeible. If 1 side looks better let that be your tank front.
Sorry the red thing is part of the shop vac after I hosed it off. I have no idea about the pump stuff. The 2 different filters were green when I took them out. In the bottom of the pump is some brown rock like chunks and some black chunk things. I am so new to all this. The guy I got it from went over it quickly, but I wish I had taken a notebook and wrote down what all he told me. I also have a protein skimmer thing that he said I won't need to use since I am not doing saltwater.