Problem filling Apollo A4 stands

Ive got a pair of Apollo A4 stands which are pretty decent and are just the right height that I need (just over 90 cms).

I want to fill them with sand in order to give them a bit more weight and tighten up the bass.

The problem is that the stands have small gaps at the top and bottom of each of their four pillars which are intended to be used for hiding cables and are very unhelpful for sand filling purposes.:crazy:

The only thing I can think of to overcome my problem is to try and tape up the gaps at the bottom with some matching coloured cellotape (silver) and then fill with sand (from b & q?) as usual.

Does anyone have any other suggestions as to what I could do?

 

Use duck tape.

 

Yes I did the same .

do dry your sand in the oven for at least 20mins at 150 degrees c

 

or you could buy kiddies play pit sans, thats been pre dried.