Hmm,

Someone in my office suggested filling a tube with the substrate you want
and somehow blocking it from spilling out, placing the outlet at the level
you want in the existing gravel and then somehow opening the bottom of the
tube. Now I've used a similar technique when using cement grouts in wall
cavities but maybe the same could be done with a funnel and hose, you'd
probably spill a bunch into the water too


"Phil Dietz" wrote in message
om...
I have a 10 gallon tank already established with plants and fish.
The floor is plain gravel (blue !!) of a larger size.

I'd like to build up a layer of substrate underneath it without
disturbing the tank too much.

I've read that clay can be made into balls, baked, then inserted into
the gravel.

Anyone try this or have any tips ?