This will almost certainly cause use problems with both cloudy water and nutrient release each time you disturb the substrate planting or moving plants. Even bottom dwellers will go rooting around in their continual search for food and cause cloudy water. Laterite should be confined to the lower 1/2 of the substrate. IOW, you should mix laterite in the bottom half and then top the laterite enriched portion of substrate with an equal amount of plain gravel/sand/substrate. If it was me at this point, I'd cover the entire substrate with at least 1 inch of additional substrate over what you currently have.