I transplant a couple of weeks into 12/12, too. As a matter of fact, the practice is recommended. It helps replenish soil and the soil buffers, gives 'em more root space, and I can adjust perlite to fit the current season/situation. (more perlite equals better drainage)
Likely they have been in the same pot a while, as it takes a couple of months for the soil buffers to deplete. This applies to any major brand of peat-based soil.

Monthly flushes to remove built-up nutrients can help stabilize the ph and remove excess nutrients and micro's.

Mixing soils from different companies is usually a bad idea, as different components can compete/amplify/interract with each other. Often with an undesirable result.

Never re-use soil unless you know what you're doing. (adjustments/ammendments necessary)

How are you calibrating the ph pen?
Rusty Trichome Reviewed by Rusty Trichome on . Ph runoff Issues So last Thursday I flushed my plants for the first time and found alarming results. Some of the plants runoff was ~ 6.2 when the intitial solution was ~6.65 these plants are not a big deal I will just water them with a 7 ph solution.:) The problem is that I have a couple of plants with a runoff of ~ 5.75 when the solution being put in was around 9 ph. So now the question is do i flush the plants untill the runoff is at a good level or do i continue to use a 9 ph solution in watering to try and Rating: 5