Just put an air stone or disc air diffuser as near as possible to the bottom drains. Placing it right above each bottom drain would be the best. The air bubbles will push water upward, creating a mushroom like current and attract all the debris at the bottom towards the bottom drain.

hello, it seems your pond is a conversion from a swimming pool, am i right? heres how a bottom drain should work, depending on the shape of the pond and water inflow from pumps,:

1) if there are a few entries of water coming from your pump to oyour pond, then the bottom drain should be in the middle of the pond, and the floor of the pond should be slanting deeper towards the bottom drain, like a v-shaped floor. the bottom drain should be at the deepest part of your v-shape floor.

2) if there is only one point of entry of water, then the bottom drain is best placed at the opposite end from the entry, still the floor should get deeper as it gets closer to the bottom drain. a design like this doesnt require u to have a v-shape floor but a floor which is increasingly deeper.

both is because water flow, even though u have venturis and jets to push debris and water towards the bottom drain, is not as vigorous as u think. so debris could still get stuck on the floor. the best method is to let gravity do its work.

3) people dont install tiles in their ponds, namely beacause algae that grow on the side and floor of the pond could be easily smudged off by the fish, resulting in ypur water floating with algae., further, the craacks in between the tiles create a settling area for the debris, so its harder for the debris to flow into the bottom drain.

it seems from the likes of it u would need a complete pond remodelling!! if u want, try and scroll tru the topics, im sure i read a few postings about converting a pool to a pond. but regardless, u seem to be only keeping gold fishes. they dun shit-a-lot!! just jet spray with your garden hose the debris towards the bottom drain once in a while.

Hi there..

i like to get my stuffs from mainland at pasir ris.. shud try there.. good luck