rock/stone selection

[Minster49]

Hi,

Are there any type of rocks or stones that shouldn't be used for lining ponds and/or building the waterfall? Thanks

Minh

[koiczar]

Yes. Stay away from any type of porous stone such as lava rock or pumice stone (aka "feather rock" ). Depending on where you live, you might want to see what rock is native to your area and sitck with that. Usually blends into the landscape well and will look more natural.

Mike

[Russell Peters]

Quote: Originally Posted by Minster49 Hi, Are there any type of rocks or stones that shouldn't be used for lining ponds and/or building the waterfall? Thanks Minh

When you say "lining ponds" are you talking about the top edge, or are you talking about inside the pond? Please keep all rocks out of the pond itself.
Also, besides the lava rock or feather rock, you want to make sure that none of your stones have sharp edges or points to them, so that you Koi won't scratch themselves.

[Minster49]

Mike/Russel,


Thanks for the response. I am planning on using the rocks to line the pond. I would like to have some of it partially submerge in the water to make it look more natural. Is that not a good idea? Also, I will be using the rocks or stone for the waterfall. Out of curiosity, I wasn't planning on using the larva rocks but I do have it in my filter for the pond...you mentioned that I shouldn't use larva rocks so I was wondering if it's bad for the water? Thanks.

Minh

[Russell Peters]

Using rocks around the preimeter of the pond, partially submerged is fine, as long as all of the surfaces of the stone are smooth. Lava type rock is not good for around the pond as it is very sharp and the fish can get damaged. Using them in a filter is a whole different discussion.

[bigred]

You can use flagstone for the edge of the pond and it comes in a varity of colors. As for the water fall I used granite and changing out the flagstone to black slate. I wouldn't recomend black slate for the edging since it can be very sharp. Also my friend outlined his pond with riverrock but the problem he has is the food ends up in between the rock where the fish can't get to it. So he had to lower the water level a bit to help with the problem.

[Minster49]

Thank you for all the response. I went rock shopping today and I really like the long rock/bolders (5'L x 20"W x 14"H). Has any one use this to line the pond? I'm sure there is risk or stressing the liner if I don't place it on there right. Ideally, I would like to have it 6-8" in the water on a ledge but expecting a person to set that big of a rock on the edge of a liner is probably a little too much to expect.


I was thinking about possible making the ledge of my 20x8 pond about 2-3 ft wide at a depth of 6-8" so that it might be "easier" to place the rock. Am I just asking for trouble here? Thanks.

Minh

[koiczar]

Minh

I have never heard of "natural" stone being so uniform in size. I have not heard of this product you're speaking of.

Having a "ledge" 2-3 FEET wide is IMHO is asking for problem as water will get in between the rock and so will debris. It will accumulate, unseen, and eventually become anaerobic. That is when trouble can start with your water quality and would be the last place you'd look for the problem to exist. 12-18" for a ledge is fine as long as you have a way to "curb" the liner behind the rock to keep the water from leaking out.

You asked about whether the rock should be partially submerged - I know what you want it to look like because we have done ponds that way. It does look beautiful, almost as though the rock is "floating" on the surface. The pitfall is that when the fish are feeding, it can get pretty frenetic and they have a tendency to spook one another while eating. If a fish is near a rock edge and they get spooked they could run right into the rock and get damaged or worse, if it's a head on collision, they could knock themselves out cold. So, I would recommend the rock be place slightly above water line and not too far out over the ledge.

Mike

[Minster49]

Thanks, Mike. That does sound rather odd...natural rock. I will probably look for some lighter rock to use for my pond. I like the big rocks but once they set the rock, it pretty much stays so it's not like I can move it around to where I like. Might throw in a couple on the ground level by the edge just for effect. I will have one shallow edge of the pond where it will be a slight slope of bed rock and small pebble. So that's probably where I will be feeding the fish. The koi I have now are pretty frentic at feeding time so I will stay from feeding them near any big rocks.

[saratogatan]

If you are in CA, I will recommend 'Yerba river Blue rock' for what you want. Yerb river blue rock has higher density that most rocks. they are harvest out of river, therefore they have almost no sharp edge. Last but not lest, the color is great.

stan