It's a tub mini pond, 45ltrs. It has gravel in the bottom & larger stones to the top on one side, so hedgehogs etc. can get out if they fall in. I don't plan to have fish. I've planted a couple of pond plants in the proper pond plant baskets, weighed down with pebbles on their top. I've also added floating plants to oxygenate the pond; all are tiny at present. I'm worried because the ones I've planted are in erecaceous soil, which I didn't mean to use. I hope this won't harm the plants & any small pond critters, or perhaps it won't make any difference?