Question
QUESTION: I am in the process of building a 5,000 gal liner Koi pond.  The landscape designer who is doing most of the work recommends that I line the bottom with pebbles and the walls with cobble stones (this would be done over the liner).   The reasons are strictly esthetic.  The pond will be lighted and you will not see the liner.  This sounds like a great idea to me, but I have never heard about doing this.  My concern is that a lot of debris will get trapped in the stones and not be cleared by the bottom drains.   What are your thoughts?

ANSWER: Dear Bill,

Thank you for your e-mail and nice to hear we have A new pond enthusiast.
You are correct that rocks on the bottom will create areas where debris will get stuck.
Also koi tend to use this to scratch themselves to it when they are having parasites.
So most koi enthusiasts will not place rocks in the pond and keep it as "clean" as possible.
However note that for some people the view is the most important and if this is the case you can try to place the rocks and keep them clean with A type op pondvac and choose rocks with no sharp edges.
The choice is naturally yours and my personal advice is to not use rocks or choose alternatives like the smooth flat pebbles or so.

Good luck and happy pondkeeping!
Kind regards,
Raf

PS looking forward to the result!

---------- FOLLOW-UP ----------

QUESTION: Raf,

Thank you for your answer.  I do have a follow-up question.  The pond will be 4.5 - 5.0 ft deep, so the bottom of the pond probably will not be as visible as the walls.  What is your thoughts on leaving the bottom clear of any stones, but lining the walls with relatively soft "softball" sized stones from the bottom to the top?  Thanks.  Bill

Answer
Dear Bill,

Thank you for the response.
Sides are also A risk for injury and algae, however also this item is more like what the goal is.
Most koi enthusiasts keep the pond completely free of rocks, edges etc. This to ensure the wellbeing of there koi as they tend to give lots of money for the koi and an injury could result in decrease of the value.
However some pond enthusiasts create A pond to enjoy as A part of the garden, completely integrated. And with this view they tend to use rocks.
Personal advice on this is to be sure no sharp edges are on the rocks and no large holes.
then it would be some kind of "ok" result for the view and for the fish.

Hope this helps.

Kind regards,
Raf