Hair, sting, thread type algae can sometimes be caused by old light bulbs, too high of watts, wrong color temp and if the light source itself is too close to the water surface...among other things....Even the partition between the light source and water can be a cause- due to light penetration issues.
Over fertilization or if water changes are not made enough or between adding ferts.
It normal and expected to get some species of algae in the tank and it can even mean the system is healthy, however, since it is a closed system-even the good algae needs manual removal on occasion-along with control.
Snails, especially in planted tanks-some common snails can be a good thing, however, they can over populate and we have to manually remove them on occasion. I like to trap them by either using a small baited jar or a piece of leafy greens-like spinach or lettuce-Place in the tank at lights out and first thing in the AM-pull them out and properly discard. I also will use a larger meshed net to collect snails that have gathered around some bait and scoop them out-This way I can also kinda sift the sand too and brighten it up some when it starts to look dingy...