How to clean aluminum water tank

[hd002e]

There are some white scaly deposits inside the alum watertank of my boat. In my previous boat I had a bladder type watertank and would simply use a bit of bleach every now and then to keep the tank clean, but I fear bleach may go into a chemical reaction with aluminum. The inspection port would not allow me to go in there and do mechanical cleaning so I need some kind of a chemical solution. Open to suggestions from aluminum tank owners.

[Wood]

Clean it as in disinfect? I use sodium percarbonate 200 gallon tank I use about 5 pounds. Let it stil for a day or so then run it through the system and fill up with fresh water. Any residual is such a low concentration not to be a health concern - in my opinion.

It will capture & remove some of the oxide and you have to keep your screen clean. I also remove filters when doing this.

Chlorine, as you know, reacts badly with aluminum. It also creates a pasty oxide that clogs things up.

My tanks are 32 years old - so don't want to tempt fate.

ETA: I also use this to clean the holding tanks and sanitary lines.