Clean acrylic tank

[scmang]

Finally upgraded from 50 to a 110!!
I got a 2nd hand acrylic tank with a few MINOR scratches. Awesome deal. But it has this algea in it, not sure if coralline or what but the tank is dry and this stuff is not coming off. I don't want to use a scraper and scratch the acrylic up. Someone told me to fill it all with tap water and citric acid and run the pump and itll come off on its own, but no recipe or how much acid, and will that have any effects of the tank when I fill it with saltwater? Still a newbie and only doing fowlr for now. Thanks in advance everyone! (Last Pic was it when it was set up)

 

[saltytanked]

Ya fill it up and run it with citric acid or vinegar. Should come right off.

 

[scmang]

Ya fill it up and run it with citric acid or vinegar. Should come right off.

How much tho, and will it effect?

 

[saltytanked]

How much tho, and will it effect?

Idk. Make it strong..
Won’t hurt the tank

 

[KrisReef]

How much tho, and will it effect?

pH <6.2 will move the calcium into solution. I used muriatic acid and lowered the pH to 2.0 and in a day the coralline algae from 10 years of growth melted.

I ran a hose to the sewer to dispose of it at 2.0. In the past I have used baking soda to neutralize the pH after I am done soaking motors, power head, to descale it.

 

[scmang]

pH <6.2 will move the calcium into solution. I used muriatic acid and lowered the pH to 2.0 and in a day the coralline algae from 10 years of growth melted.

I ran a hose to the sewer to dispose of it at 2.0. In the past I have used baking soda to neutralize the pH after I am done soaking motors, power head, to descale it.

So as it breaks down the algea in anything less than 6.2, scrape it, drain it, let it dry out and then I can fill with salt water?

 

[KrisReef]

So as it breaks down the algea in anything less than 6.2, scrape it, drain it, let it dry out and then I can fill with salt water?

That worked for me.
And just to be clear, the liverock and sand were removed from the tank before filling with fresh tap water and acid to descale the tank, and pumps and other equipment, if you like. Wear gloves and goggles when working around acid!

 

[scmang]

That worked for me.
And just to be clear, the liverock and sand were removed from the tank before filling with fresh tap water and acid to descale the tank, and pumps and other equipment, if you like. Wear gloves and goggles when working around acid!

Ok that's awesome, and yes thanks for the gloves warning. Muratic from the pool store? Or citric?