Pond liner thickness, bell siphon, tight outflows - beginner questions

[Louise]

Here are some more beginner's questions:

I'll be lining my grow bed in my first ever AP system with pond liner. Do you have any recommendations on the thickness of pond liner?

Any tips on how to make good, tight outflows through the liner?

I'll try to build a bell siphon like this one: https://www.youtube.com/watch?v=oDzcKgWLRf0&feature=related

Any tips or warnings?

Thank you!

Louise

[Vlad Jovanovic]

Weyowey the attachment worked :) anyways...see if someone here has a bit they could sell/trade if you don't need a lot of it.

EDPM fish pond liner is another popular one. But, try not to get the 'regular' black EDPM cuz it's not safe for the fish ( or hence you, I'm guessing).

I've heard of people using some of the greenhouse )hoop house coverings too. But do your research, some of its prob not as durable as others...

[Patti Taylor]

Thanks Vlad,  getting a few quotes now.

[TCLynx]

Beware lumber/liner (even treated lumber) within sight of dirt in termite territory.  At least here in FL, termites can fly so being able to inspect for tunnels in not a guarantee that you are safe from termites.  I have replaced all my lumber/liner beds now either with stock tanks, barrels, metal and liner, or Towers.

If beds will be very rectangular, then the Durascrim is very good liner.  It is stiffer than the EPDM so harder to fold nice corners and anything beyond simple corners gets really tricky since it is stiff.  The EPDM is far better for more complex shapes and in ground ponds or folding a round tank out of a square piece of liner.  EPDM (Firestone Pondguard) is good and Just liners Plus will probably have a good price for you.

[Patti Taylor]

Got a 6'x50' roll of DuraSkrim for $153.60 with free shipping from www.buyplasticsnow.com .Thanks again Vlad.@TC don't they have Terminix in Florida.LOL, I cant stand termites they ruined a porch I built in VA.I built my system on gravel and off the ground so I'm hoping the no soil contact and treating the surrounding area will help in prevention.  .

[TCLynx]

I'm not into spraying poisons around my system.  And that space between liner and lumber tends to stay moist since the liner will be cool when the water floods it so condensation will keep that area moist even if there are never leaks.

[Patti Taylor]

What are the alternatives TC?Can I use some type of membrane in between that space to alleviate the moisture .Maybe some Dow board  might work .Is there anything organic I can use to deter the termites?.I've even looked at the seal-it-green products to petrify the wood somewhat ,but that stuff is toxic to fish.Sorry for all the questions but I'm new and confused at all this.

[Vlad Jovanovic]

I think styrofoam or extruded polystyrene (Dow blue board) might help with the condense issue, but how that relates to the  termites...? TC or someone else will have to field that one :)

[TCLynx]

I've simply removed the wood from the equation.  I now build my liner beds using metal rails and I clamp the liner to the rails.  Either resting on the ground and the sides exposed (if you wanted to put foam around the outside you could but that makes me fear that perhaps bugs or rodents could be nesting between the liner and foam.)  Or if I want a waist high bed, I use some cattle panel or other sturdy fence or nursery bench type metal supported by the metal rails under the bottom of the liner.  This works for light weight media though starts to become a bit more costly to support a heavy gravel bed.

[John E Windsor]

TC, I want to build a 4' x 20' DWC using a sheep/goat feedlot panel (from TSC) for the walls. I am assuming it is sturdy enough, maybe with the help of some steel fence post, to do the job. I need to take a trip out to TSC first to check it out. My question is what do you use to clamp the liner to the top of the panels?

http://www.tractorsupply.com/feedlot-panel-sheep-goat-16-ft-l-x-48-...

I am thinking the Firestone EPDM pond liner will work well here.

I'm glad I found your statements here. I was about to start putting this together using pressure treated lumber, against my better judgement. So, I started doing a little research before I jumped in and once again you have steered me in the right direction.

Thanks!

TCLynx said:

I've simply removed the wood from the equation.  I now build my liner beds using metal rails and I clamp the liner to the rails.  Either resting on the ground and the sides exposed (if you wanted to put foam around the outside you could but that makes me fear that perhaps bugs or rodents could be nesting between the liner and foam.)  Or if I want a waist high bed, I use some cattle panel or other sturdy fence or nursery bench type metal supported by the metal rails under the bottom of the liner.  This works for light weight media though starts to become a bit more costly to support a heavy gravel bed.

[TCLynx]

Uh, no I would not recommend building the DWC using the feedlot panels as walls.

Ya wanna come up and visit and I can show you how I'm doing the DWC beds here?

I have done a bed using cattle panels but then I had to add fence posts and wires across the top and after all that, there are better ways to do it.

I would use Durascrim liner

Fence top rail type conduit and snap clamps

[Jim Troyer]

@ alex  I am going to throw this out there because I have been wondering about elastomeric roof coatings for waterproofing wooden tanks, so... What does the esteemed panel think about elastomeric roof coatings?

[John E Windsor]

I was thinking of cutting the panels down to 16" and adding steel posts on the outside for added stability. It would be built on the ground, so it really isn't that tall. I saw the pics you posted of the taller, maybe 4' tall, round panel structure and I can see where that might of been less stable.

I appreciate the invite for a show and tell. Perhaps some time in the near future we will take you up on that.

Can you send me a link where I can look at the Durascrim? I am only looking at a 20' x 4' rectangle, so I don't need a lot.