Do I really need an adapter for every pedal I have plugged in?

Every pedal I have is a Boss pedal and I want to use my DS-1, DD-3 and GE-7 all at once but I've tried using my two adapters, one plugged into the DS-1 and the other the DD-3 and I get a crap signal that keeps fading (I'm sure I've heard that you can run two pedals on one adapter)

These Boss adapters are £20 and I can't really afford to keep buying them everytime I get a pedal.
One, providing you get one thats current output exceeds the withdrawel of the pedals.

A 1A (1000mA) should cover you... Im running 7 pedals all off one adaptor atm.
check out the one spot from visual sound. they work with all of boss pedals. i got one and it helped with buzz and other noise.
Just curious - Does anyone know how much the PSA-240 adapter is meant to be able to run because I have two of them and as I said I can't run three pedals.

Is the One Spot a lot more powerful than the PSA-240 then?