Plumbing and Piping - Toilet Problem (Air in Lines)

We have a two story house with three water heaters, elec in attic, elec. & gas on first floor. We are also on well water and septic. Sometimes, but not always, when I run the water in the kitchen, (first floor) the water in the sink has such a tremendous force of air that it spits out and water goes everywhere. Or when we flush the toilet, first floor, it honestly sounds like the tank is going to explode. This isn't normal pipe knocking, this is scary! It sometimes happens on the second floor, but very very rarely. This house was plumbed in the 1980s with additions now and then. Any suggestions on this? Hubby thinks the water is drainig down from out of the pipes upstairs and causing air to replace it, but I'm not so sure. At any rate, we need to fix it! Thank you.

bnbmine, Welcome to the DIY Forums.
Lots of things to check. Air can enter the waterlines in various ways. One of them is from bad washers in fixure faucets. When the faucet is closed, water pressure seals the washers tight but when a faucet is opened, it can suck air. My first choice would be to replace the loud toilets fill valve. Get a Fluidmaster 400A fill valve (about$6). They have great installation insructions. Good luck and let us know if this helps. Good luck.

Replaced the fill valves, but that didn't do it. Could it be coming in from the well tank? Someone said the storage tanks from the well have a rubber bladder that may have a hole in it. Would that make air enter the pipes? Thank you.