Thanks for looking.
Just installed 2 new toilets. Each one is losing water from the bowl.
Also, when I flush one, the water in the other one starts to drop or has a wave action
Went to the roof vent with hose and flushed for a long time.Then sent the running hose in 19 feet ( which should be well past toilets )
No improvement.
Thanks for any ideas !

Does sound like you are getting a siphon action. What is the distance roof top to basement floor plus 20', cause that is how far you need to rod, put the hose away.

Thanks for jumping in !
Hose away.
I'm just a hacker , how did you figure the rooftop/basement floor +20.
( when you say rooftop,is that height of roof vent ? )
Thank you again for your input.

Went to the roof vent with hose This time rent a sewer snake and take it back up on the roof. Your vent's blocked and the vacuum is pulling the water out of the bowl. Put out enough snake to reach the base and 20 feet more. Good luck, Tom

Thanks .
Is a rod the same as a sewer snake ?
Should it be manual or powered ? Roof has a pretty sharp pitch...
With that +20 feet, I'm into the drain to the septic right ?

Is a rod the same as a sewer snake ?
No! A rod is a flat tape while a snake is a coiled cable.

Should it be manual or powered ? Roof has a pretty sharp pitch...
Powered, (see image). The vent can only be cleared from the roof, be careful up there.

th that +20 feet, I'm into the drain to the septic right ?
Yes, once you get to the base 20feet should put you out into the main.
Good luck, Tom

Thanks Tom,I appreciate your help, I'll be going back at it this weekend, I'll let you know how it turns out.