I purchase min from Home Depot whenever I go but I just found the non branded version on Amazon. Just search “Sprite filtered shower head”
Sprite SL2-CM Slim-Line 2 Universal Shower Filter, 1.5 pounds, Chrome https://www.amazon.com/dp/B00154Z61I/ref=cm_sw_r_cp_api_glt_fabc_G3Z3AQPDEE7HS1CTR9ME
I have used this this one one for years and it softens my water! I was having really dry, itchy skin when I move to my apartment so I got this and it feels just about the same as the water softener system my parents had when I still lived at home.
I haven't tried any other ones but I really like the sprite one! You can find it on amazon as well.
This is the one I got from my lowes https://www.amazon.com/Sprite-SL2-CM-Universal-Slim-Line2-Shower/dp/B00154Z61I/ref=sr_1_5?crid=3S3IA2KGP7X6Q&dchild=1&keywords=sprite+shower+filter&qid=1602289304&sprefix=sprite%2Caps%2C282&sr=8-5
Probably a filter like this one. When you go through the number of months it is rated for you change the filter
Here is the actual product
https://www.amazon.com/Sprite-SL2-CM-Universal-Slim-Line2-Shower/dp/B00154Z61I
Under $20! I got this cheap Sprite water filter because it fit my shower and they have it at my nearby Lowe's. There are tons of cheap well-reviewed ones on Amazon.
I use one of these inline shower filters
Replacement filters are cheap and readily available at Home Depot.
It's a little inline filter for the shower head. Lowe's sells them for ~$20, with filters at ~$10.
https://www.amazon.com/Sprite-Slim-Line-Universal-Shower-Filter/dp/B00154Z61I
I live by Sandalwood (north of UNF) and I had to get a shower water filter because I live by the chlorination plant. I couldn't get my hair clean https://www.amazon.com/gp/product/B00154Z61I/ref=s9_al_bw_g60_i3