All, I just joined this Forum after looking around on it for the past couple of days. I’m very impressed and discouraged with the level of knowledge that everyone seems to have about building and maintaining ponds. I’m discouraged because I’m starting with zero knowledge and I appear to have a steep learning curve. Normally, I would take the time to educate myself on something like this before attempting this type of project, but not this time!

I’m currently in the process of having my small pond dug for LMB fishing and my operator (35 years of pond building experience) suggested that if I let him line the bottom with some ‘blue shale’ that it will last longer and help keep the water clear. I can’t seem to find any reference to this on the Internet so I was wondering if ya’ll could help….. Is this a good idea assuming it isn’t going to break the bank? What are the pro/cons of doing this?

Thanks,


Jeff

JDH welcome to the PB forum. We all started with no knowledge and had people help us along the way. That is what this forum is about.

I have not heard about "blue shale". Can he tell you what it is and why having a rock lining is needed? Most rock will over time sink into the bottom and or be covered with silt. We use gravel/rock for fish beds and swimming areas or structure. Lets see what others say.

I have drilled quite a few wells, for cathodic protection of a pipeline, in the Colorado area. We typically always hit blue shale at depths of 200 feet plus or minus. The blue shale has a lot clay in it and was ideal for anodes placed in it. Thats about all I know and as far as using it for a pond bottom, I'm not sure, but it does have a fairly low resistivity for conducting DC current coming from the anodes. So I guess I'm saying it is a naturally occurring soil layer in quite a few states, at different depths.

OK, I did some more research on blue shale it it appears to be some type of clay. From what I understand it is very dense and will hold water well. My operator told me that I already have a good clay bottom so I don't understand how this is going to make it better. I'm not even sure if you want the water clear..... Is there any issue with clear water?

Hey JDH...welcome to the show!
I've been hangin' back cuz I don't know dittle about blue shale (and most of the other things these guys discuss ), but there's no chance that he said, or meant to say, blue clay...? Blue clay is a pondbuilder's gold bullion.

Clear water is great for swimming and looking but not so good for raising fish because it is plankton (base of the food chain) deficient . The bottom is only part of the "clear equation" as you can have green water in a swimming pool . Soil suspension is one clouding event and a plankton bloom is another. A rock or clay or sand bottom does not preclude the second. So it depends on what you want.

OK.... I think we are on to something here. I did some more research and it turns out that blue shale is blue clay. Thanks for helping me unravel this mystery!

So my goal is to build a pond for LMB fishing..... With that goal in mind, what are the benefits of lining the bottom with blue clay? I’m looking of the pros/cons to determine if the added cost will be worth it.

Water clarity: Is there a benefit to clearer water? Would I get more plankton growth due to the sunlight penetrating deeper? More O2? Or will it just allow more weeds to grow deeper along the sides?

Why do pond builders call it gold bullion? Is it as good as gold or cost as much? ;-)


Thanks for sticking with me on this one!

Assuming you will not have a suspended soil problem without the blue clay then it should not effect water quality . If ponds in your area have turbidity (suspended soil) problems and the blue clay will stop that then you should consider it. The main benefit of it would be in an area with low rain fall and soils that tend to leak. Its main benefit is to help keep water in the pond from absorbing into the soil. I hope that helps some.

Yes, that does help! I'm going to wait to hear the price, but I'm thinking it is overkill. I'm already over budget, but I thought if adding the blue clay would help down the road, then now is the time to do it.

Thanks for your help..... I hope some day I can return the favor