Nirvana Spa near Reading are doing 2 for 1 on their experience days.
Valid for 12 months from date of purchase.
The two offers are:
£73.50 - any evening session (5-10pm)
£105.70 - any Day session (Mon-Thurs. 8-5pm)
Entrance (usually £35 per person as "friend" of guests)
Towel & Robe hire (usually £5.00 +/- per person)
Dinner from the buffet (Usually £10 per person)
Soft Drinks (Usually about £2.00 each)
Flotation with Induction (Usually £32.20)
Usual cost per person: £84.20 - x2 = £168.40
So, as you can see it's quite a bargain.
I'm personally a member at the Spa, and can thoroughly recommend it.
TIP: If you do go, don't shave (anywhere) the day prior as the Flotation will be murder.
Just pack some flip flops & your cossie / trunks.