Hard water build up

I just got a used 55 gallon tank that is very dirty and has some thick mineral deposits on the glass and hood. I have been scraping and scrubbing and can't seem to get the stuff off. I can scrape off the top layer but it still looks foggy. Tried softscrub, Kaboom cleaner, vinagar and brillo on the hood so far. How about CLR anyone know if it works? Any suggestions would be appreciated, Thanks!

razor blade works on the glass and some parts of the hood, but i can't get some stuff on the little tank i bought either.

CLR works really well, but I would not use it on a tank of mine for fear something being left behind to poison the fish.

Use vinegar should wipe it right off....dilute 4:1 for general use or straight on the tough spots

That is an awful lot of chemicals listed above.

soft scrub, kaboom and brillo are going to kill your fish. The tank is no good for fish now. It seeps int the silicone and releases into the water for years.

i think he only used it on the Hood, not the tank. that's the way i read the post, but i could be wrong.

I heard "the works" works well and you can get it at walmart I have 2 friends that say they've used it many times to clean tanks.

Yes I just used the chemicals on the hood. Thanks for the suggestions everyone most of the problem areas are on the hood. I'm still working on it, just alot of scrubbing!