Iron removal. Act Carbon and Manganese combined in 1 filter???

Would very much appreciate some feedback on some well water treatment issues.

We have a whole home treatment system consisting of 1) small plastic sediment filter 2) large standing stainless filter containing both activated carbon (top) combined with Manganese Greensand (bottom) in one unit 3) large stainless filter containing Ion Resin. Then treated water tank and pressure pump.

I’m not certain the advice we have received is correct, particularly in combining the activated carbon and Manganese in one filter. We have a problem with occasionally having very black water seem to be flushed out, particularly after power outages when the pressure pump tank gets completely emptied. This black contaminate seems to accumulate in there and possibly pipes as well. It looks like little bits floating in the water in such a concentration that it is very black. I suspect this is activated carbon residue caused by the softer act carbon being broken up by the harder Greensand, I’ve come across 1 or 2 posts that says combining these is not advisable, but not certain as this is how we were directed to set up our system.

Our Iron level in the water is 0.5 mg/l, I think regularly this should be below 0.3mg/l. We have the water softener which I understand may be effective in treating this. We’ve had a water test, the iron is being treated but I don't know how much by the Manganese and how much by the Resin, and I don't have a reading on the water hardness.

I’m considering taking out the Manganese and just using Act Carbon in one stainless filter and Ion Resin in the other, and relying on the resin to eliminate the Iron content. Another reason for taking out the Manganese is that we are not regenerating it, just regular backflowing (we do regenerate the Ion Resin with salt). Would that work? Am I likely to get staining at that Iron level if we are using the softener?

Thank you very much for any advice you can give!

Mike