The size of air bubbles that support the sand, has crucial impact on how a sand picture actually works. The rate at which the sand falls and therefore its final effect depends on the size of the air bubbles.

Due to the properties of silicone glue (the glue that holds the panes together) the quantity of air in a picture may vary. These changes can occur over a long period of time (from a few weeks to a few months) and can be caused by pressure, temperature and humidity.

In order to enjoy a sand picture for many years to come, a simple adjustment of the picture should be made. Sand pictures should be adjusted according to the following guidelines. The best effects will be obtained when air bubbles support the sand on the whole length of the sand picture, allowing grains of sand squeeze themselves through the air bubbles, as it is seen in the middle picture below. If you are not satisfied with functioning of your sand picture, follow the instructions below:

There is too little air inside. How to add some air?	The quantity of air is perfect. See the effects in our sand gallery.	There is too much air inside. How to decrease the quantity of air?

How to add some air into a sand picture?

	If there is too little air inside a sand picture, the sand moves and falls down too fast and does not create any interesting compositions. In order to obtain right quantity of air, and thereby proper functioning of the picture, the following actions should be taken.
	In order to carry out adjustment of the sand picture, a syringe (capacity 5 ml at best) and a sharp needle (thickness 0.5 mm) are needed.
	Take the syringe with the needle. Take in a little of cold boiled water and make sure that there is no air in the needle (it prevents blocking up the needle while piercing the silicone).
	Find an opening in the frame of the sand picture.
	Pierce soft silicone, which joins the panes, through the opening, gently probing with the needle (check if the opening inside is not covered with sand). Next, suck about 0,5 ml of water with the syringe.
	Remove the syringe from the opening. The air will get in through the needle, replacing the liquid.
	It is necessary to check whether the pressure in the sand picture is the same as the pressure outside it. You can check it by gently pressing the panes of the sand picture with your fingers a few times.
	If the quantity of air is right, remove the needle from the sand picture. Put the sand picture in its initial position and trickle the sand a few times. If there is still too little air, repeat the actions starting from the second point.     If it turns out that there is too much air, move on to option: How to decrease the quantity of air in a sand picture.

How to decrease the quantity of air in a sand picture? 

	Too much air inside a sand picture prevents the sand from falling down and the picture actually does not work. In order to obtain right quantity of air, and thereby proper functioning of the picture, the following actions should be taken.
	In order to carry out adjustment of the sand picture, a syringe (of capacity 5ml the best) and a sharp needle (of thickness 0.5 mm) are needed.
	Take the syringe with the needle. Take in a little of cold boiled water and make sure that there is no air in the needle (it prevents blocking up the needle while piercing the silicone).
	Find an opening in the frame of the sand picture.
	Pierce soft silicone, which joins the panes, through the opening, gently probing with the needle (check if the opening inside is not covered with sand). Next, add about 0,5 ml of water using the syringe.
	Remove the syringe. Added water will replace the air.
	It is necessary to check whether the pressure in the sand picture is the same as the pressure outside it. You can check it by gently pressing the panes of the sand picture with your fingers a few times.
	If the quantity of air is right, remove the needle from the sand picture. Put the sand picture in its initial position and trickle the sand a few times. If there is still too much air, repeat the actions starting from the second point.     If it turns out that there is too little air, move on to option: How to add some air into a sand picture.