Every 2 or 3 days is good, if the water starts looking murky you should refill the tray immediately using the easy flush system method.

Yes. I Re Grow is made from a clear durable BPA FREE plastic that is dishwasher safe.

At least more than 60 herbs, veggies, fruits and spices can be regrown in water.

Yes, as long as it fits in the holes, or you can always take the top off and use with container alone.

Yes. Removing the lid allows for regrowth of larger plants.

Typically water only, however you can add small amounts of nutrients, distilled water works great for regrowing purposes.

ill until plants are slightly touching water, reduce water when roots are present, let roots only touch water, submerging plant in water too deep may cause plant rot.