Strange 'residue' on my scalp

I have had dreads for a while now, long enough for my scalp to acclimatise, but I am still getting a kind of residue building up on my scalp when I leave it more than 3 days to wash my hair, I think it is just my scalp skin cells with natural sebum but when I scratch my head it comes off quite thickly under my nails - kinda ewy. I do a lot of sport so I suppose it gets quite hot up there a lot. I don't think this residue is visible until I physically scratch it off, but I want to know if this is normal, and if possible how I can prevent it? My worry is that on thicker dreads it will be getting into the middle of the dread and if I don't wash my hair so thoroughly by accident it might be doing something nasty in there. 

Any help would be FAB ⭐️

- I have caucasian, very thick, straight, long hair naturally

- I have never used wax or any other type product

- I spray diluted tea tree oil in my hair maybe once or twice a week on my scalp, and occasionally rosemary oil too.

What you describe sounds very normal to me. I think you are right that it is dead skin from your scalp. If you do a lot of sport, your head gets hot and sweaty and while doing sport the blood flow is pretty hight underneath your scalp. Maybe that causes more dead skin is coming off your scalp or just quicker than without sport? You could try to wash right after sport or do a cold water rinse right after to get the sweat off your head and cool down your scalp. I do sport too and i know what you are talking about. I think it can get itchy because of the remaining sweat on the scalp after a workout.

I do wash my hair once or twice a week, but take a cold rinse inbetween washes when i feel the need for it. It closes the pores of the skin and the hair get less oily than without it. Maybe just give it a try?

it might also be sebum mixed in  

but yea its kinda normal, are you washing with something good

--
My new book Ban The Taboo Vol 1

I have exactly the same problem. I think it's just a whole lot of dandruff. I've had this problem for a very long time, just since having dreads those flakes don't have much space to move, so they tend to stick very close to the scalp. When I scratch my head near the scalp I just get tons of that white stuff under my fingernails.

I doubt there's much that can be done here, I also got a lot of dandruff even in my beard.

I guess the only solution would be a great anti-dandruff product which would also be appropriate for dreads, but I haven't been able to find anything like that yet.

what are you washing with now and how often

--
My new book Ban The Taboo Vol 1

Well right now I'm using Dollylocks liquid shampoo, which I strongly suspect doesn't work in hard water. I'm washing once a week but sometimes even less because I'm kinda lazy washer.

i used to love maleys gardens (and still love the sweety that makes them) but they to had the issue in hard water

--
My new book Ban The Taboo Vol 1