what are water crystals?

[Bravo123]

what are they? I want to go buy some at home depot but I forgot what they were called. they are for my dubia colony. i know it must not have any fertilizers or additives so if anyone can help me and my beardie would greatly appreciate it.

 

[foolsgold]

polymer water gel

 

[Sapphire]

They'd be in the lawn & garden department, called "Water storing crystals". There are various brands. I use the Miracle-Gro brand, just make sure it's 100% polyacrylamide (check the ingredients) and you should be good.