This was how the Sungai Rambai BH owner keep his BH humid.
He keep water inside lots of plastic containers.
The containers were all over the place and I told him that I will create those pools to store water.
The pools will be about 8 feet by 12 feet and on each floor I will install at least two.
The water will be about 2 inches deep and it will have about 8'X12'=72 square feet of exposed water surfaces.
This will make the BH humid and much easier to top up if the water dry up.
To avoid mosquito from breeding I sprinkled about 2 packets of abed-e powder.
The good thing about the use of this technique as compared to those wet floor is that there is no need to carry those fine sand upstairs.
The task to carry such a heavy load deter the operation.
Have a look at a few of these ponds supplemented with a few chicken coop humidifiers.
I reused the containers since they do served to humidify the BH.
Also wet the floor.