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 covered 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!