Many thanks for your recent enquiry regarding the self watering tray kits and water tubs we supply, and the possibility of using these products in unison.
It’s not really necessary to use the water tub to replenish the watering tray as the latter has a reservoir of between 18 and 30 litres (depending on the size of tray). The capillary matting which comes as part of the kit - and which we also sell independantly - draws water from this reservoir and remains damp, allowing the plants’ roots access to water. Once the reservoir runs low, it’s a simple task to fill it again and the cycle continues!
The water tub is best suited to keep capillary matting damp which is placed on a greenhouse staging or bench with no reservoir or other means of drawing water. The tub is supplied complete with a ‘wick’ of matting which transfers water from the tub to the main section of capillary matting. Again, it’s very easy to fill the tub as it becomes empty.
Hopefully this explanation of how the two products work will clarify why the two are not often used together – and of course will help you decide which product best suits your needs.