How to avoid over inflating a tube

[happybob91]

So I'm embarrassed to admit this but I just had to buy my second replacement air bladder for my float tube. Generally what can I do to be more careful? I bought an air pressure gauge so hopefully that helps, but today I was at a reservoir, with the air temp in the 70's, with the water being cooler. I took it out and inflated it, as it seemed to be deflating a bit. When I filled it up it seemed firm, but I heard that dreaded hissing sound. Any advice would be appreciated!
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