New pond

[Richard Porter]

hi can anyone offer any advice. I am having two ponds built. One top pond falls into bottom pond. I will try to include a diagram. What’s the best liner ? Have bought 11 litres of rubberised pond paint but builders are talking about the fibreglass you use on flat roofs. Not sure which would be best. Also how to I sort out filtration. Has anyone got any plans they can share for something similar ?

 

[Lisak1]

Welcome! The very best pond liner is always 45 mil EPDM. Not sure if that's what you mean by the fiberglass they use on flat roofs. EPDM is used on roofs, but it's not fiberglass - it's synthetic rubber. Is your builder familiar with ponds? Or are they just constructing the framework? It appears you are planning for a raised pond.

The way you've drawn your pond it appears you plan to have plants in the top and none in the bottom. The top "pond" could instead be build as a planted wetland filter. You wouldn't need any additional filtration. Search this site for "bog filter" and you'll see lots of examples of that style of pond filter. You also show a bottom drain in your design - are you planning this pond for koi?

 

[Richard Porter]

Landscape gardener is building ponds with some advice from a chap who has some experience with ponds. I sort of wanted a wildlife more natural pond on the upper level and a deep ‘ uncluttered ‘ bottom pond. A mixture of fish including a few koi would be good. 11 litres of rubberised pond paint has just arrived and so I guess that’s what I will use to paint. Was thinking of getting external pump at bottom pond level to pump up to eazy pod auto at top level pond and then run back into top pond through the plants , weed and over waterfall into bottom pond. Really not too sure. I may have bitten off more than I can chew ! To a certain extent budget is not a real issue. What I don’t want to end up with is a big green bog

 

[Richard Porter]

I think I’ve come to a decision ! I have done a bit of reading and spoken to a few guys and it looks like the best idea is to go for the upper pond as a bog area and make the whole thing as natural as possible. The way the area is split in two levels seems to make sense to not over complicate things and go this way. I guess you can still have some water depth in the top bog/pond for a few small fish ? So basically just need to pump water from bottom pond up to top pond. Up through layers of gravel and back into bottom pond ? I guess no need for UV or is there ?

 

[Jhn]

Yes on pumping up then gravity fed back down. Depending on how you set up the bog you could have pools of water in it by keeping the gravel low in spots. Most fish aren’t going to stay there though unless they can’t get out.

No there is no need for a UV.

The only thing you need to add to your system is some type of settling tank for the bottom drain. You don’t want it really feeding directly to a pump.

 

[Richard Porter]

Or maybe forget the bottom drain and just use a good quality internal pump at bottom of pond ?? Had conflicting advice re bog filter. One chap said use pipes to fill from bottom up to surface and another said if you do that all the plant roots will just block the pipes over time so just feed water slowly over top of gravel. Any thoughts ? Also how deep should gravel bed be. One chap says no more than a foot and others say as deep as possible?? Thanks for help btw

 

[Jhn]

I would feed up from bottom. Check the top of this forum for addy1’s stickied thread “Bog Building” she describes in detail how to build an up flow bog.

As for bog depth mine is about 18” or so, but some go much deeper. I would go at least 18”, also choose your bog plants carefully avoiding the ones that send out deep roots.

Letting water flow slowly over the top of the bog will not be as effective as the up flow version. The water slowly trickling over the top will tend to channel over time and the plants while still in the water, won’t have the desired contact time with nutrient rich water from the main pond.

 

[Mmathis]

@Richard Porter Hello and welcome!

I am amazed at how quickly you were able to get with your chaps as well as do so much research and come to all these conclusions in such a short period of time! Wow, it takes most of us days, weeks, sometimes months to process all of this information! And after @Lisak1 suggested looking up “bog filters,” you mentioned that you didn’t want one of those green bogs. But glad you decided to listen when your guy suggested the same thing! And even more amazing is how similar your conversations with them almost exactly mirror some of the things we talk about on GPF regarding bogs (for example, how deep to make the gravel bed). Awesome! Bogs are great filtration.

Keep up the good work with your research and planning! Be sure to take lots of pictures to share. We love to see others ponds and follow their progress. It’s one of the ways we all share and learn from each other. We’re here to help and answer questions!

 

[j.w]

@Richard Porter

 

[Panzer13]

Welcome

 

[sissy]

if you put epdm over concrete you will trap water between the 2 .The epdm will start to float

 

[addy1]

. One chap said use pipes to fill from bottom up to surface and another said if you do that all the plant roots will just block the pipes over time so just feed water slowly over top of gravel. Any thoughts ? Also how deep should gravel bed be. One chap says no more than a foot and others say as deep as possible??

My bog is filled from the bottom, mine is deep, 2.5 feet, mainly because I sort of went crazy with my tractor.
27x4.5 feet, 2 2 inch pvc pipes running the length, 38000 lbs of pea gravel. Full of plants my one and only filter. The water is consistently crystal clear.
I had bogs in the past that had down flow ie. over the top of the gravel. Over time the gravel was covered with gunk and the water over flowed.

I have never had plant roots block the pipes, most of the plants in a bog stay shallow. Grasses, rushes are the only ones I have had go deep. They maybe go around 10 inches down.

Depth of gravel I would go at least 18 inches, deeper if possible.

Welcome to our forum!

 

[addy1]

Not the best shot, just pulled from the cams, this is how clear my water is. Just love my bog. Part of it is at the top of the picture.

The round pots are oil pans with lilies in them. I have not done my normal shallow water move yet.

 

[Richard Porter]

I have had a radical rethink and got a pond expert in to design. Got to be right. No bog going in anymore. Will update soon

 

[Mmathis]

Oh, OK. Just curious, but what changed?