Pond substrate??? Please help

[Autumnsky]

Have 120 gallon preformed pond, above ground, and would like to have ideas about substrate... I have 4 1.5 y/o butterfly Koi +/- 8" and 2 small comets 3-4". I am looking to get a larger pond this year when I find a good deal.

Last summer I added water lettuce and water hyacinth and fiber optic grass but too cold and couldn't keep them in the house, so I will be replacing them this year and keeping an eye open for a hardy option for here in Northern Colorado. Suggestions welcome!!!

So far my trash can filter is doing a great job of keeping the pond readings good, but I would like to add some rock, pebbles, gravel, or something which would add some contrast to see the fish better and add to the beneficial bacteria levels .

Found a good deal on Jelly bean rock from Caribsea, and tiny rounded river stones 1/8"-1/4".

I vacuum the bottom once a month on average, more in the hot months.

Sand blasting sand??? or stone from the local river from the sand plant down the road? pea gravel?

What size would you advise, having sand in the aquarium, I am familiar with how easy it is to suck up your sand in the vacuum, but I could put most of it back, rocks just seem to trap debris, so I am thinking the tiny rounded stone mix...atm?

Any experience, pros/cons??? Ideas???

Thank you!

 

[chagoi]

No substrate. You dont need & it's hard to clean.

 

[Autumnsky]

Thanks, and also someone else reminded me Koi/Goldfish like to eat rocks if they can fit into their mouths.

Still looking for others experiences/logic-mainly from the BB aspect of adding stones.

 

[Darth Sorcerer]

Substrate?

You Do Not want sand in you pond as it Will Breed unwanted bacteria, Stick with some larger rocks to give your fish a little atmosphere and something to pick around.Look around the internet for DIY Bio-reactors these are vessels filled with "kuldness" not sure of the spelling,this is the very best bio system that you can provide to keep your fish healthy and your water ideal,bioreactors are very cheap and easy to build.Also I agree that you require a larger pond as a koi is not like a goldfish that will only grow to the size of there pond,the koi will continue growing to their genetic asigned size,perhalps a little slower,but may become hunchbacked and deformed. I too started with a small pond,believe me a larger pond is very much easier to keep stable! Hope I have helped you with your pond. PS. Koi Do Not eat stones,but they do mouth them to suck off any nutriants