black spots inside aluminum tank??

[Rooster1]

Is this the first time you looked in these tanks or have you looked inside the tanks previously. If you have seen the inside of the tanks prior to this; are the stains something new this time?

stains on one of the tanks were new

 

[Shiprekd]

It might not be mold, there are many tanks that come straight from the factory with black stains on the inside.

I was in Fl and stopped on my way back out and picked up two brand new Catalina AL80's. When I got back and had my LDS VIP them, there were black like splatter marks in the bottoms/sides of the tanks. The LDS said they've seen new AL's come like that quite a few times.

Since then they've been through quite a few fill cycles and hydros and they're still going strong.

While that may or may not be true for this instance, it does happen as you mention.