I've worked out how to have a long, hot, deep bubble bath without using up a quarter of the bottle of bubbles first and leaving most of the liquid bubbles in the bath... don't know why I didn't think of it before now!
It's simple really!
You run the hot water tap and slowly trickle the bubble bath liquid into the tap water from as close to the tap as you can get!
Up until I tried it, I had been putting 4 or 5 glugs of bubble bath into the water which used just under a quarter of the bottle each time
I've had 2 baths using this new method and I've used 2 blobs down the side of the bottle in those 2 baths instead of half the entire bottle!
In theory, if I keep using this method, I'll get 10 baths out of one bottle instead of 4!
The depth and heat kinda go hand in hand. You fill the bath quarter full with just hot water, trickling in the bubble bath, then you turn the hot tap off and get in.
Catch your breath... it'll be hot!
When your breath has recovered, fill it up until just over two thirds full and relax.
Let the boiler re-fill and re-heat before you put any more hot in.
Wait until the water has cooled down to warm then empty most of the water out... it should be deep enough to cover your feet then fill up with hot water and relax again.
Repeat as often as you want... the bubbles will stay at the top of the water for pretty much the whole length of a long bath, so stay in for as long as you like! Family permitting of course! lol