Pond without liner

[Jmacaddy36]

I am completely new to ponds so please excuse me if any of my questions are obvious.

I have a drainage pond which was dug about 8 years ago, it was 4 feet at the deepest then but is now only about a foot deep because the bottom has become filled with leaves and debris over the years. It is 15x30 feet.

1. Could I re dig this pond to be deeper and have it hold water without a liner? I live in an area which was a former gravel pit and we have clay soil.
2. Can I have goldfish in a more natural pond like this? I won’t be able to have power out there but I could use solar air pumps.
3. Can goldfish be kept with native sunfish?

For reference, I am experienced with planted aquariums and have a decent understanding of the nitrogen cycle and fish care.

 

[hamstermann]

Bentonite clay will hold water but it will almost never be clear water. Regular clay won't hold water - it will seep through it eventually.

As long as the water chemistry (ammonia, nitrates, nitrites, pH, hardness) are within healthy levels goldfish should do fine. You'll want filtration and a way to oxygenate the water somehow.

I don't know anything about sunfish.

 

[Mmathis]

Hello and welcome! I have no idea, but where do you live (climate zone)?

 

[Jmacaddy36]

Southern Michigan

 

[GBBUDD]

Bentonite clay will hold water but it will almost never be clear water. Regular clay won't hold water - it will seep through it eventually.

Not so. The right clay will get saturated it gets wet to a point and can absorb no more. Can it leach through more and more clay yes I supose little is truely water PROOF but true clay and the correct thickness will hold water quite well.
But the fish will constantly turn up the surface as the top layer is pure mush and the water will always be turkey. Even adding bentonite with makes for a tighter seal will not stop cloudy water.

With 15 feet wide 4 feet deep and you have access around the pond that's high and dry yes a large excavator can reach . Quite likely from one side and a mid size could reach half way from both sides.

If you want to have clear water I would throw I liner is but I would look at hdpe over epdm. Easier to work with is a muddy sediment.

 

[GBBUDD]

Blue gill can not eat mature gold fish but they will keep the gold fish population under control by eating the fry

 

[Jmacaddy36]

Not so. The right clay will get saturated it gets wet to a point and can absorb no more. Can it leach through more and more clay yes I supose little is truely water PROOF but true clay and the correct thickness will hold water quite well.
But the fish will constantly turn up the surface as the top layer is pure mush and the water will always be turkey. Even adding bentonite with makes for a tighter seal will not stop cloudy water.

With 15 feet wide 4 feet deep and you have access around the pond that's high and dry yes a large excavator can reach . Quite likely from one side and a mid size could reach half way from both sides.

If you want to have clear water I would throw I liner is but I would look at hdpe over epdm. Easier to work with is a muddy sediment.

I really don’t want this pond to have a liner because of price and because it is a drainage hole first. Currently the pond has remarkably clear water, although it is tannin stained.

What if I put pea gravel on the bottom to separate the fish from where the muck is?

Will the plants actually keep the water clear or will they just remove nutrients?

In how deep of water can cat tails grow?

 

[j.w]

and welcome @Jmacaddy36

 

[hamstermann]

Not so. The right clay will get saturated it gets wet to a point and can absorb no more. Can it leach through more and more clay yes I supose little is truely water PROOF but true clay and the correct thickness will hold water quite well.

That hasn't been my experience at all. Most ground in the wasatch front is pretty heavy clay soils - we're the bottom of ancient Lake Bonneville and have mostly clay because of it. Water doesn't percolate down through the clay soil like it does with sand or a good loam, but it eventually does perc through. Bentonite is the only clay that I know of that supposedly doesn't do that. All of the clay that I've worked with/around has drained. It does it slowly, but it does drain.

What if I put pea gravel on the bottom to separate the fish from where the muck is?

I thought the bottom of your pond was sandstone? are you worried about the fish poop and plant material turning into muck again? A skimmer should help with leaves and stuff, and the fish poop should break down into nitrates that the plants would use.

Will the plants actually keep the water clear or will they just remove nutrients?

removing nutrients fights the algae and it keeps the water clear that way. Plants on the banks could fight erosion and keep some mud out that way. floating plants might catch leaves rather than letting them sink, but you'd have to clean those up regularly as well.

In how deep of water can cat tails grow?

I dunno.

 

[Jmacaddy36]

I thought the bottom of your pond was sandstone? are you worried about the fish poop and plant material turning into muck again? A skimmer should help with leaves and stuff, and the fish poop should break down into nitrates that the plants would

Why do you think the bottom of my pond is sandstone? Right now its just clay topped with muck. Cant do a skimmer since I don’t have power unfortunately.

removing nutrients fights the algae and it keeps the water clear that way. Plants on the banks could fight erosion and keep some mud out that way. floating plants might catch leaves rather than letting them sink, but you'd have to clean those up regularly as well.

That makes sence.

This pond drains about 2 acres, so it doesn’t need to completely hold water, just hold it well enough so that it doesn’t drain before the rain refills it.

 

[hamstermann]

Why do you think the bottom of my pond is sandstone? Right now its just clay topped with muck. Cant do a skimmer since I don’t have power unfortunately.

I must've mixed yours up with someone else's that I was reading about. Sorry about that.

 

[Jmacaddy36]

I must've mixed yours up with someone else's that I was reading about. Sorry about that.

No problem

 

[GBBUDD]

What if I put pea gravel on the bottom to separate the fish from where the muck is?

The pea gravel will sink into the clay , eventually it may stop but that can be a heck of a battle, sand maybe a beter option as by weight it would be comparable and not sink in ass fast.

Will the plants actually keep the water clear or will they just remove nutrients?

They pull nutrients out of the water . and if water is forced through their roots it ca work as a filter. aka bogs/ wetland filter

n how deep of water can cat tails grow?

Cat tails in a natural pond is an eventual death sentence for the pond. cat tails can take over a pond 3 feet in depth or less

Bentonite is the only clay that I know of that supposedly doesn't do that. All of the clay that I've worked with/around has drained. It does it slowly, but it does drain.

No their are many types of clay . red, brown, tan white and gray , trust me clay alone can totally water proof a pond without the need for bentonite. . i believe 6 inches of gray clay is all thats needed to do the job. Its very much like modeling clay add water and the outside turns to mush while the center remains dry UNTIL

 

[Jmacaddy36]

The pea gravel will sink into the clay , eventually it may stop but that can be a heck of a battle, sand maybe a beter option as by weight it would be comparable and not sink in ass fast.

Ok

They pull nutrients out of the water . and if water is forced through their roots it ca work as a filter. aka bogs/ wetland filter

Ok

Cat tails in a natural pond is an eventual death sentence for the pond. cat tails can take over a pond 3 feet in depth or less

Experiencing that with the old pond now. Cleared a lot last summer but at one point they covered the entirety of the pond.

No their are many types of clay . red, brown, tan white and gray , trust me clay alone can totally water proof a pond without the need for bentonite. . i believe 6 inches of gray clay is all thats needed to do the job. Its very much like modeling clay add water and the outside turns to mush while the center remains dry UNTIL

Cool