My tap water is 0.05 EC - do I need calmag?

Hey guys, my tap water comes out as 0.05 ec which is about 25ppm. Should I be adding cal mag to it to make up for this?

The reason why I ask is that I've been experiencing very slow growth atm and after reading another post on the forum, I'm beginning to wonder if it's my water not my setup as I first thought

Thanks a lot!

Gonna answer my own post here lol, but for anyone else wondering about low ec tap water and calmag, you do need it! It would also explain the slow growth i have been experiencing too so =D