Is it open for swimming

Yes

I would call them but since the water maintains the same temperature year round i think they would remain open unless the outside temperature is too cold. You can swim we got off the tubes and swam then jumped back on tubes but it is a little difficult getting back on tubes if you are older but i did manage it. People take snorkeling and eye wear for water cause there is tall grassy bottom so you may see fish otters and other wildlife under water. Saw a small gator so some are there too but i feel it was a safe place cause of so much activity.

Sure is...the head of the srings is most popular...but they charge admission...we stayed at the campground...no charge...same true for the tubbing center although officially closed, we biked in