acrylic tank help please

[scary]

I have a 29 gl hex acrylic tank. It has been set up for one year contains
2 clowns several hermit crabs 1 yellow and fuscia gamma ??
35 pounds of live rock and a bottom of live sand
I have the most horrible algea problem.
Atleast I think it's algea, it is green and some is kinda purple growing all over the acrylic in little kinda deformed circle patterns. I can hardly see in the tank anymore. I tried to scub them off early on and they were tough to do. Now they are very hard to scrape off. I then let the tank get away from me and now as I said I can hardly see in. Everyone says scrubbing it will just scratch the acrylic. How do I take care of this without losing my fish and everything in the tank.
Or must I just let it go and try to start all over again? Any info on this please. Thank you!!

 

[phixer]

Can you drain you temporarily drain 1/2 of your tank water into an intermediate container like an open plastic barrel then carefully move your fish into that, drain the rest of the water into the barrel until the tank is empty of water. Carefully use your bare hand to scrape off the algae or a soft sponge. Then then relocate the tank to area with less natural light. Maybe you could take a sample of the algae place it in a tupperware container while your doing this and take it to a local botanist or botanical gardens for identification then ask them what this type of algae responds too, what makes it thrive, i.e light, water chemistry, bacteria etc...and then alter that parameter, or before you start do some research to find out what fish will eat the algae and will be compatible with their other tankmates then possibly add these fish to your tank if your water chemistry will allow it.
Phixer

 

[aw2]

No need to drain your tank...
Your LFS should carry plastic scrapers, specifically made to scrape algea from acylic. If they dont, use an old credit card, grocery store card...something along those lines. That'll work just fine.
It'll take some elbow grease...just make sure you keep up with the scraping, after it's clean.