CRYPT FILTER; Advice on Support Mesh

[NiftyFifty]

Getting close, folks, but I need a little input from you all. I’ve built my waterfall and solved the issue of coral rock porosity for the waterfall. Before I fill the pond, I have to finish my filter and need advice on what to use for support mesh for the filter media (see description and pics of the design way down, continued in comments).

POND INFO: I am in Salt Lake City, UT (USA), Zone 5 (Google says coldest average temperature is 29.2°F/-1.6°C). I inherited this pond with my house and I believe the pond was built in the 50s or 60s. The pond appears to be built out of cement, is approximately 20’x20’ (6x6 meters) with sloping walls towards the center, and about 5 feet (1 1/2 meter) at the deepest part. I’ve been trying to rehabilitate the pond and figure out some of its odd features, including what *might* be a weir (for another post) and a crypt like structure in the middle of the pond.

Photo #1: The pond in May, just started draining it

Photo #2: June, after draining and removing about 3 feet (1 meter) of gravel

(Continued in comments)

 

[NiftyFifty]

The crypt is approximately 6.5’ x 3 .5’ (16cm x 106cm). It is made with thick cement walls that are about 6 1/2” wide (17cm) and extend about 2’ (61cm) high from the “bottom” of the pond. There is a pit inside the crypt that descends another 2 or so feet past the bottom of the pond. Each of the 4 crypt walls has one 2” (5cm) drainage hole which allow water to drain from the outside of the crypt into the deep pit. There are 6 steel bolts that extend up from the crypt walls.

 

[NiftyFifty]

FILTRATION:
In addition to a small planted stream that will feed the waterfall, I’ve decided to use the crypt structure as a physical and biological filter.

CRYPT FILTER DESCRIPTION:
The pump is placed inside the pit. It pulls water into the pit from the pond and pumps it up to the stream, which leads to the waterfall, which fills the pond. As a side note, there will be a planter built directly over the crypt filter (but more on that in separate post later).

FILTRATION:
PART I; “TOP FILTRATION”
This step of filtration pulls water into the pit through filter media that covers the *top* of the crypt. The filter media is supported by a 2 stainless steel frames (2 separate frames so I can access the pump by lifting one of them out) and stiff stainless steel mesh in top of that. The stiff wire mesh is secured in place by fitting it over the 6 existing steel bolts on the top of the crypt walls).

2 frames fit over top of crypt

Stiff wire mesh lays over the frames to support sheet of activated charcoal and blanket of blue pond filter media.

(continued in comments)

 

[NiftyFifty]

Water flows into the pit through a sheet of activated charcoal and a blanket of blue filter filament that is help up by wire mesh and stainless steel frame that is fitted onto the crypt walls.

ADVICE NEEDED

Ok, so here is my current situation and where I need advice. As I was assembling the filter, I discovered that I am unable to bend or cut the wire mesh down to the correct size and I can’t cut holes in the mesh in order to fit it over the steel bolts. The wire is too thick.

A friend who is an engineer was helping me at the beginning of this project. He drew the plans for the 2 stainless steel support strut frames and bought the stainless steel wire mesh that’s supposed to go over the frame to hold up/support the activated charcoal sheet and filter filament. However, he can’t help anymore so I’m on my own.

I could buy some bolt cutters and try to cut the holes needed to fit the metal mesh over the 6 steel bolts. However, I’m concerned that it might be too difficult for me to use bolt cutters as I’ve never used them before. Wondering if a non-muscular middle-aged person such as myself could wield bolt cutters and then actually cut through the metal.

Yesterday, the guy at the hardware store suggested I use a rotary tool or angle grinder, but honestly, I’m a little afraid of power tools and can’t afford to buy them right now anyway. The other thing is that these metal mesh sheets are slightly larger than the crypt so my friend had planned to bend/fold them to fit over the crypt walls. Unfortunately, I am not physically strong enough to be able to bend this mesh.

So, I am considering possibly using a finer mesh (like chicken wire or garden fencing) that’s covered with vinyl. Something not quite as stiff as the wire mesh I had planned to use, but easier to cut and bend. Vinyl covered to give a little protection against rust at least for the short term.

Alternatively, I am considering using a plastic mesh. There’s no rusting with plastic, but the only plastic mesh I can find is this stuff and I’m not sure if the filter media might get pulled through the holes?

What do you think? To protect the exposed cement from freeze thaw, I believe I need to fill the pond before winter really sets in. If you were in my position, would you use one of the vinyl coated wire meshes, that orange plastic mesh, or would you try to use bolt cutters on the wire mesh I already have? Or possibly something else?

NOTE: Although I obviously don’t want anything to rust, I think a little rust is ok since I am going to do some rebuilding next summer when it’s warmer. I only need these materials to hold for this year.

Thank you so much!

 

[NiftyFifty]

In addition to being a non-muscular middle aged person, I am afraid I am also quite a technophobe. Can I edit posts?
——
I should have said that the wire mesh I am thinking of using (instead of the thick and very stiff stainless steel wire mesh that I currently have) is vinyl *coated*. I didn’t want there to be confusion when I called it vinyl covered above. I’m thinking of using one of these products:

The guy at the hardware store also said I might be able to use galvanized wire instead of vinyl coated wire if I plan on replacing it. He also suggested spray painting it, but it is too cold now to spray paint outside. Again I plan to replace this mesh with something more permanent in the summer.

I am grateful for any advice you have! Thank you!!!!

 

[mrsclem]

I would stay away from any galvanized wire. The zinc coating can be toxic.
I got plastic mesh fencing from Lowes that has 1/2" holes. you should be able to get it on-line.

 

[Mmathis]

Did you ever find out FOR SURE, what the crypt actually is?

 

[NiftyFifty]

I would stay away from any galvanized wire. The zinc coating can be toxic.
I got plastic mesh fencing from Lowes that has 1/2" holes. you should be able to get it on-line.

I did not know that about galvanized wire, nor did I know about the existence of plastic mesh fencing! Brilliant! Thank you so much

 

[NiftyFifty]

Did you ever find out FOR SURE, what the crypt actually is?

It remains a mystery!

 

[NiftyFifty]

I would stay away from any galvanized wire. The zinc coating can be toxic.
I got plastic mesh fencing from Lowes that has 1/2" holes. you should be able to get it on-line.

Yay mrsclem!!! I found and ordered some plastic “chicken wire” and I think it’s going to work really well! Bless you for your suggestion.

Super easy to cut and rigid enough to hold the filter cloth and activated charcoal sheet.

Why does it look like Christmas you may ask…
Well, the day I was assembling the filter, it seemed like the last warm day we would have in SLC, so I decided to spray paint the bolts and stainless steel frames after all. I got a can of Rustoleum primer/paint in a greyish-beige that kind of matches the color of the cement. But I ran out of that quite quickly and the temperature started dropping. I was afraid I wouldn’t have time to go back to hardware store to get more of the grey-beige color before it got too cold to spray paint. Luckily I had several cans of Rustoleum from another project in my basement. And so, at least for this year, the filter frames have to be fire engine red!

I could only find blue filter media sheets in 1 foot width rolls so I have to sew about 6 of those together to cover the frame. I’ll slip that and a sheet of activated charcoal between the two layers of plastic mesh. I’ll update with photos.

Thanks so much for your suggestions!

 

[NiftyFifty]

It remains a mystery!

Also, a new guy at the hardware told me “For sure that’s an old fountain!” But I don’t know.

 

[NiftyFifty]

UPDATE! Here’s a photo of my filter in place. It took me a while to sew the blue filter panels and charcoal fabric to fit the space. I spent a lot of time looking for sheets big enough to cover the approximately 6’x3.5’ top of the crypt, but I ended up sewing smaller pieces together like a patchwork quilt and then assembled it last night (by the light of my iPhone flashlight🕯). Thanks again for the wonderful suggestion to use plastic fencing mesh, mrsclem!

Today I planned to assemble the island on top of the crypt. However, I’m distracted by a potential problem with sealing the gap between the old rusted steel pipe and the flexible accordion pipe that that I fit through it. The black flexible pipe moves water from my pump (placed in the bottom of the crypt) through the steel pipe in the cement wall of the pond, and then up to the top of the waterfall.

You might be able to see from the photo above, the pipe is several feet below the waterline, so I need a strong seal to keep water from draining out of the pond. The flexible pipe is quite snug inside the steel pipe, but there is a gap that needed to be filled in order to keep water inside the pond.

A guy at the hardware store suggested I spray this foam into the gap…

He seemed legit because he said he used to build ponds for a living. So I went ahead and sprayed the foam into the gaps and then some. I made an ugly mess out of it as I tried to make sure the spiraling indents on the black flexible pipe were covered. Ugh!

However, this morning I was reading some random posts on this site and came across a comment from GGBUDD about foam not being waterproof and that it always leaches water.

Do you all think I should cover this foam glob with some silicone caulking? Or do you think Rescue Tape would work (it says it’s waterproof and airtight).

 

[GBBUDD]

Sorry i'm late to the party here, yes that pond foam is Not waterproof it will slow a leak down to a trickle but yes if your looking for water proof i would trim back the access of the foam just leaving it in the gaps and then apply a good quality caulking i prefer polyurethane caulks over silicone and if you would truly like something that will withstand the test of time. for spanning the box depression i would use anb aquablock but one that i never put together b ut use the pieces to use to span across the opening. . the also have a diverter plate they sell that goes on top of the aquablocks and they are like 2 aquablock pannels. https://www.aquascapeinc.com/products/flo-cell-30mm-drainage-cell

 

[NiftyFifty]

Sorry i'm late to the party here, yes that pond foam is Not waterproof it will slow a leak down to a trickle but yes if your looking for water proof i would trim back the access of the foam just leaving it in the gaps and then apply a good quality caulking i prefer polyurethane caulks over silicone and if you would truly like something that will withstand the test of time. for spanning the box depression i would use anb aquablock but one that i never put together b ut use the pieces to use to span across the opening. . the also have a diverter plate they sell that goes on top of the aquablocks and they are like 2 aquablock pannels. https://www.aquascapeinc.com/products/flo-cell-30mm-drainage-cell

You are not at all late to the party! I’d say you helped me avert a huge crisis once I filled the pond and discovered the leak that would surely occur. Thank you so much!

I understand about trimming the excess foam and applying caulk. It’s *very* good to know that polyurethane would perform better than silicone. Thank you!

I don’t understand how to use pieces of aquablock to span the opening or using a diverter plate. I think I’m a bit clueless about some construction terms. Case in point, I just googled “box depression” and the only thing I came up with is that it is a treatment for seasonal affective disorder. I scrolled lower to see if I could find an apt description for what you’re talking about and found “Building Connections” so I clicked on that. It told me not to isolate myself. lol.

Thanks for your help, GGBUDD!

 

[NiftyFifty]

At long last, Filter Island has been assembled!

I had lofty visions of using proper materials and executing the project with excellent skill and workmanship — now I’m laughing at my folly.

The Dream: Drill tidy little holes near the top of pvc pipes for attaching plastic ties to secure the frame that holds up the island.

The Reality: I went nuts with duct tape.

The Dream: Secure the rigid wire mesh using beautiful Japanese square lashing

The Reality: As I began losing my light, this is what happened

———————

Last week I attached the coco coir and started experimenting with rock placement on the bigger island.

I spent the next day emptying out leaves and cleaned the pump before lowering her back into the depths of the crypt.

Yesterday I filled the planter with pea gravel and planted iris and blue arrows rush.

The Dream: Fill the pond and start the waterfall. Sit back, relax, and enjoy the show!

The Reality: As I was planting, there was a huge leaf drop from the tree above and within 2 hours the whole thing was covered with leaves. Why didn’t I think to get leaf netting?!!! Perhaps I’d better get one before I fill the pond?

NETTING:
Although I have a pool net for fishing out floating leaves, I worry about leaves that I can’t get before they sink to the bottom. I know the extra nutrients from decomposing leaves may create an algae problem when it warms up, but for now it’s not necessarily an issue because I don’t have fish. I won’t put any fish in the pond until I can see if my system works. I’m hoping my crypt filter keeps leaves out of the crypt and away from the pump.

I realize this is sort of dumb, but how would leaf netting work on this pond? Obviously the netting catches falling leaves, but do you take it off after the leaves have fallen?
•Does the net cover the pond and the waterfall?
•How big of a net would you need for an approximately 20x20’ pond (plus waterfall)?
•I imagine I need to figure out how to prop up the netting in the middle of the planted island?
•Leaf netting looks pretty fragile, would it break on the coral rock, and if so, I guess I’d need to figure out how to create a frame for the netting so it doesn’t get stuck in the “prickly” bits of coral?

Any suggestions? Thanks!