Remember when you were advised to use a heavier wire... just in case?I have a 240V 200amp main service with an 8/4 run of about 50ft to a sub-panel in my garage on a 2-pole 40amp breaker.
How much more power do you need?(now) I want to extend from this panel to a pool house
Do a complete load calculation this time so you KNOW how much powerIdeally 50a, but 40a should be fine.
Thankfully I put it in a 3" conduit...
is needed and then upsize that by 20% or more.
The short answer is to pull back the #8 wires and re-feed the garage panel.
You might be able to reuse the #8 for the sub-sub feed out to the pool.