Uhoh Big mistake (layered substrate opposite)

Are the fine pebbles like sand? If it is sand it would have done that anyway even if you put the flourite on bottom and the sand of top. I you have to different size substrate like what you have, the bigger part of the substrate will become on the top and the smaller ones will go to the bottom.

Like chiclidkeeper said...depends on the size difference between the substrate.

If it's similar in size and color, I'd purposely mix it all up. If not, then the finer substrate will settle to the bottom over time. Just take out all the pebbles and use all Flourite. =P