This is weird. I bought the Hayward Aqua Bug auto vacuum because my friend had such great experience with his. But, after running fine for a while (greater than 30 mins), MY bug sometimes gains buoyancy and floats up to half way or even all the way to the surface -- while running.

I can't figure it out. I've made sure to get all the air out, and it runs fine for a while. How is it getting air in it to float up?

Anyone else come across this?

I'm considering buying a baseball bat donut to weigh it down more.