my red oscar that is around 7 inches has started laying on his side and scraping himself along the stones on the on the bottom of the tank and every now and then you can see he has scraped his scales and it looks like it hurts..

normall behavour or not??

he has started getting a little nasty towards my albino oscar and the pleco again but he goes through stages of agression and peacefullness..(maybe he is actually a she) lol

I don't think is a huge problem if your fish only do it every now and then, fish will get irritants occasionally. However if they are doing it on a regular basis this could be a cause for concern. Fish will scrape themselves against objects if they have an infection of the skin, often parasites. So if your fish is doing and a regular basis, you might have to treat the tank with a parasite medication. However, try on observed the skin t and see if you can see anything that doesn't look quite right. The Odyssey don't want to medicate the tank for my reason.

both my oscar are looking pretty scraped up but then i supose thats just oscars for you.
i did a water change today. resulst of the test before hand were...

nitrite 0.25
nitrate 25-50
ph 6-6.5
amonia 0.2

i realised this week that 2 weeks ago i filled my tank up from a hose and forgot about the fact i have a filter inside my tank so i pretty much think i killed that filter off so thats why some of my reading are not that good im thinking. it was an ameture mistake which i have learned from lol.

i will watch the oscars close but im off on holiday on sunday morning for a week so heres hoping they will be fine

I always turn my filters off when putting water back into the tank, even though I have put water conditioner in first.

Your water conditions are not ideal unfortunately. Having said that, you are lucky that your pH is so low, ammonia is less toxic with a pH below 7.0, once the pH rises above 7.0, ammonia becomes much more toxic to fish

yeah, the pleco really needs to go

Hi
I would say that your nitrates need to be down to below 10 if you could. Your's is way too high and could kill your fish.
The best way to start lowering the nitrates is to keep up on water changes. If you do that then your nitrates should go back down to normal.