Mineral tank question

I have a 8*44 mineral tank that is about 1/2 full of active carbon media, can more be added or is there a certain amount of upper space needed for it to run properly. My control head has a top basket to keep the media from being backwashed out.

Thanks

The empty space is needed and called freeboard. The mineral expands upward into the freeboard space during backwash.

Usually the freeboard area is 50% of the bed depth not to includ the bowl shaped top and bottom areas of the tank.

Would this amount of mineral be about 1/2 cft then. I forgot to ask when they installed in.

An 8 x 44 usually holds 3/4 cuft. For a carbon filter, there should be a top basket to keep the carbon from being backwashed out of the tank. If you only havea 1/2 cuft, then there may be no top basket and you've lost carbon out he drain line.

The only way to know these things for sure is to ask those you bought it from or get a local dealer to come out and check what mineral and how much of it etc. BUT... a 8x44" tank isn't going to be large enough for most homes.