How much Citric acid

[PeterEde]

So I bought a 2nd hand XL425 and am running fresh water through.
I have cleaned as much as I can by hand.
Is it still worth running citric acid and if so how much is required to make a strength enough to remove gunk?

 

[DJF]

https://www.reef2reef.com/threads/citric-acid-concentration-for-cleaning.285372/

 

[Uncle99]

So I bought a 2nd hand XL425 and am running fresh water through.
I have cleaned as much as I can by hand.
Is it still worth running citric acid and if so how much is required to make a strength enough to remove gunk?

I’d keep citric acid for pumps.
Vinegar would be much cheaper if just glass.

 

[tzabor10]

You can’t mess it up as easy as vinegar. I add about a cup to a gallon. Time also plays a factor. Good luck