I have been taking Psyllium powder for years.
I have a method you can use where the powder mixes completely with water. You need to have or buy a screw on type water bottle or glass container. Put the water in the vessel , then the powder. Immediately screw on the top and shake the mixture for about a minute. Drink that portion and then add some water, shake again-to get the remaining small bits - and drink that up. Rinse or clean the container immediately to avoid any small pieces to stick.
I have never had any more problems with clumps or lumps. It mixes up more like a milk shake. Hope that helps.