Wheel's Patio Pond Project

Delays, delays, delays.

Pond: Here's my PVC planter holder/tank divider in place with the 24" planter installed to rough out the look. This is just preliminary placement stuff to get an idea of what I can get away with.


I have the two kidney-shaped baskets that I want to clip to the sides of the stock tank. I got some stainless steel wire specially to make the clips, but it turns out 3mm hard stainless steel is pretty tough to mangle into shape! So I'm trying to figure something else out to mount these. But they fit the curvature of my tub's sides very well, and I can even move the right one further towards the back to leave room for the waterfall return.


Aquarium: I'm getting hung up on substrate options. I need something that works with an undergravel filter: sand and kitty litter/oil absorbent are usually not recommended for those. Trying to find something that won't break the bank: specialty aquarium gravel is highway robbery these days.

Drilled a hole for the power cable. Going to use my usual RG6/U rubber weather boot for a grommet as I did with the last few DIY iterations. Almost feel guilty having kept these from my ISP job (they were in my cargo pants pockets for easy reach and I forgot to take them out before leaving).

The chuck of white plastic on top is an off-cut from a sheet of 13mm polyethylene I'm going to put on top of the tank stand for the tank to sit on; another take-home from the new workplace. They were going to throw it out because it got a little shattered underneath a press. I was able to get some one to cut it to size for me, and the plan is to Krylon + clear coat it to protect it from UV damage and help it blend in with the all-black tank furniture.

Putting some clear coat on the parts for the light fixture housing after painting it. Same black Krylon Fusion and Fusion clear coat as the PVC plant holder. It may not have worked out for my foam shells but at least buying a shit-ton of these two has given me plenty to work with on other things!

As with the plant holder parts, I hit the PVC surfaces with some acetone to prime them before applying the paint.

Defenestrar said:

Regular gravel picked up from the side of the road after a winter traction graveling and wash it?

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There's considerations to this.

The ideal substrate is aquarium gravel, about 3-6mm in size. but that's stupid-expensive for the quantities I want on these two projects. Like, upwards of $1/pound, and I'd need a couple hundred pounds for these projects. I'll consider it my last resort.

Smoothed pea gravel is very nearly the right size, but it's too rounded and mostly too large. It makes for big gaps where food and detritus can accumulate in a way that the filter can't take care of.

I'm looking at landscaping suppliers for aggregate options, but most are either too big (57 stone is about 5 times too large) or too dirty (crusher run and quarry screenings, usually unwashed and made for compaction which is what I want to avoid) or they only goes down to rounded pea gravel.

I need something like sized/washed chat or buckshot gravel, and I can't seem to find that stuff locally.

I'm leaning towards pool filter sand, which is designed to let water flow almost unrestricted. I kinda hate the light color, though. I've got my Black Diamond as a very affordable (~$12/50lb bag) dark-colored alternative. But I'm reading a lot about sand-type substrates being problematic with under-gravel filters... just short on details WHY or any experiences people have had with it.
The usual line is about compaction blocking the flow and defeating the filter, especially with the cheapest stuff like play sand (which isn't carefullly screened and has a lot of "fines" or dust and compacts readily).

Another possible option is calcined clay stuff: kitty litter or oil absorbent, which are just types of clay that have been calcined (baked below the sintering point so they're not hard-fired ceramic, but still fired hot enough not to dissolve into mud when left in water).

I have a bag of unscented non-clumping kitty litter which is the "right" kind for aquariums, and it's cheap of course, but it's a bright white-gray color and I don't like that. Still, I'm testing it in a jar of water to see if it gets muddy or clouds the water too much.
I also have a bag of Safe-T-Sorb from Tractor Supply Company, and it looks great: dark black-brown, hasn't turned to mud in my test jar yet. Bonus: It's super cheap at like 30 cents/pound.
But I'm getting mixed signals on whether these can be used with an under-gravel filter.

Also, there's just a lot of bad information floating around as "truth" in the fishkeeping communities, especially about filtration and substrates. A lot of it is third-hand knowledge passed off as fact, and undoubtedly a lot of it is based on the marketing needs of the equipment sellers.

Doesn't help that it's a holiday 3-day weekend so my options are even more limited than usual.

Pea gravel (especially the rounded "river" variety) is what local shops and suppliers carry. It's getting to the point that I'm seriously considering buying a cubic yard and sieving down to 3-5mm on my own.

It doesn't help that there seem to be several overlapping terms for the kind of stone I want, that vary by region (Midwest versus PNW versus Northeast vs my area).

There are also some more, rather obscure options. A type of washed and sized large-grained sand used for grip when epoxying decks is offered as an option but there seems to be exactly one place on the Internet that sells it, everything else is Google trying to send me to Home Depot for composite deck planks in "sand" color or telling me how to lay sand underneath my deck or how to sand a deck with sandpaper, or something equally stupid that I can't dissuade it from shoving in my face.

I swear there's something else called "filter gravel" that's different from pea gravel, even get a few hits for pool supply places... halfway up the Atlantic coast, unfortunately.

With Google search being absolutely wretched now, I'm not getting a lot of hits that are relevant for other options. Even when I try verbatim results or quotes and -flags it still throws up 90% irrelevant results that I'm trying to screen out with my negative terms. God I miss the Internet of 15 years ago.

That's some good advice and is something I'll have to consider, but honestly I probably won't go that direction. I'd sooner give up on sand than do a half-and-half 'scape.

I'm speculating the biggest problem with sand and UGFs may be the biofilm will cause it to clog even if the actual sand grains don't compact. Asking around for some more insights in other places.

Defenestrar said:

I know you sometimes have to be careful not to disturb a thick sand (or soil) layer in a closed ecosystem as a lot of anaerobic bacteria can live down there and produce toxins that accumulate and/or get produced quickly when introduced to too much oxygen. I don't really remember the specifics, but it is something to consider for sand/soil layers.

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If you're using a UGF then there are no pockets where water doesn't flow, so that shouldn't be an issue... in theory The whole point is that water is constantly flowing across the entire substrate. Of course, the recommendation is to avoid sand for UGFs.

(Also, it's basically impossible to get anaerobic conditions in an aquarium. The part about bacterial toxins accumulating is true enough.)

Cool Modine said:

Keep in mind that “pool filter sand” is intended to be “where food and detritus can accumulate” so that may not be what you want.

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The same could be said of sponges. As long as water is flowing through it well enough, it's not an issue. PFS is supposed to let water flow between the individual grains relatively unimpeded; they use "sized" grains that are all within a narrow range of diameters to ensure there's space between them and they can't pack together too tightly.

I think for the aquarium I'm going to abandon sand-type substrates. I tried some Safe-T-Sorb (calcined clay oil absorbent, like kitty litter on steroids and a nice dark color instead of off-white) by washing it and keeping it in a jar full of water, but although it doesn't dissolve into mud it still puts a lot of dust into the water even after a thorough rinsing. Also, probably not great for a UGF either.

I think I'm going to go with gravel. I can suck it up and spend about $50 for the amount necessary to cover the bottom of my tall and narrow tank, ORRRRRRR I could spend like 15 dollars on some hardware cloth and go to a local landscaping/mulch seller who offered to let me sift through his smallest grade of pea/"pathway" gravel at a price of $10/10gallon bucketload. I think I'm going to give that a try when I get a chance this week.

Not counting the materials I already have and the cost of my free time, I should be able to put together a quick and dirty sieving screen out of 1/4-inch hardware cloth and some spare 2x4 lumber off-cut that's been in the garage for over a decade at this point, with the gravel, for a total of about $25 and have way more than enough gravel... if it works. And if it goes well I might even keep the remainder and use it in my pond instead of the Black Diamond.

To that end, I'm building the frame. I cut up some of that lumber into 2 foot-long pieces and 2 10.5-inch pieces, but one of them split itself down the middle and I don't feel like making another so I put some Titebond across the split and have it clamped and setting up for tomorrow.

For the hardware cloth, even though I'd prefer a hole size of 3/16" or smaller, I think by doubling-up on 1/4" (one panel offset from the other by a wire's width) I can get something that works. So I'll build the frame, staple the screening to it, and take my bucket over to the mulch place when I get an opportunity. Yet another impromptu DIY sub-project.

Well it sorta works! I tested it on a bag of pea pebbles we had handy and it does screen out the bigger chunks.

Went from this:



to this:



Some build pics below. I omitted the most pedestrian things, like cutting to size etc.



The finished product, which produced the sized gravel above:




Gonna call the mulch place and try to get there after work sometime this week. It'll probably take a few trips since my screen is small. I built it to fit over my buckets, not a wheelbarrow.

It's even slower-goinger than I thought.

I tried it with two double-handfuls of gravel and came out with this, which I thought was pretty promising!




This is a little more than an hour's work:


They took pity on me and said I could come back and finish up later as they were closing for the day.

GodFather said:

At this point maybe spending the $50 would have been worth the time savings?

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It's actually working out pretty well, For ten bucks I'm getting an amount of gravel I can barely carry to my car. I don't mind a little physical work outdoors, in fact it's a pleasant and quiet break from my physical work indoors at a noisy factory up the road from this place.
Anyway, I filled the bucket up more than halfway with only an hour's sifting today. Gonna call it quits after tomorrow (assuming the weather holds). Definitely got my money's worth on this.

Gravel get.

Now the washening begins.



FIrst round with a mere scoop of the stuff in a separate bucket? It's gonna be a long shower.

Lots of clay dust. The worst dust. This stuff might not run clear after 100 gallons have been expended.

But damn, the stuff I've got looks freakin' fantastic when it's cleaner.

Let me preface this by saying "I should have just bought the store gravel."

Do not repeat my mistakes.

So the gravel still isn't coming clean. I can scoop some out and wash small amounts of it in a bucket under a raging torrential spray from the hose and it still stains the water orange from the clay mud that caked it all in the big pile where it's sat for, I dunno, years? I can fill and dump ten times and the water doesn't get measurably more crystal clear beyond a certain threshold.

So, like, don't source aquarium gravel from a landscaping supplier. Just don't.


That said, now I'm committed.
I'm buying a super cheap 330GPH transfer pump and a 10" whole-home filter housing (like the one installed in my crawlspace). I'm going to throw together a screened intake and an agitating spraybar out of PVC pipe. I've got some MIP and MHT to 3/4" ID barbed nylon fittings, and PLENTY of spare 3/4 hose from the pond pump I bought.

So here's what I'll do. I'll put the intake AND the agitating spraybar into the bucket with a small amount of gravel, fill it partway up with water, connect the intake to the WHF, the WHF to the pump, and the pump to the spraybar.
The intake will go directly to the WHF first, then through the pump, and finaly out through the spraybar into the bucket of gravel.

It'll be a recirculating, agitating, clay-dust-filtering setup to conserve water and wash this freakin' gravel but good. And it should waste way less water than spraying into the bucket and dumping it back out.

If this doesn't get the gravel reasonably clean, I'll either call it quits and buy real aquarium gravel OR finally get that ultrasonic cleaner people have been pushing me towards in the Fountain Pen thread.

Defenestrar said:

So...
Um...
Uh...
I'll leave out the unhelpful commentary and laughter.

I'm impressed. Honestly.

If that setup doesn't work the engineer in me might suggest plumbing water in through the bottom of the bucket and creating what's called a fluidized bed (flow sufficient to lift the gravel but not all the way up and out the top).

Another possible approach would be to put the gravel in a net bag/basket and suspend it in a creek for a day/week/whatever.

Click to expand...

Believe me. I have thought about a fluidized bed.

I just doubt it would do the job if this doesn't. That's why I'm contemplating getting a cheap ultrasonic cleaner. Also used by rockhounds for getting exceedingly fine dirt out of specimens they like which, hey, was another thing I've had on my list for a while.

And yeah, I'm waaaaaaay overboard at this point and I knew it when I started sifting my own gravel from a 10-foot tall pile of rocks. But half of the reason for this diversion is getting to play with other stuff while nominally moving towards this goal. It's scope creep, but at least it's kind of fun scope creep.

Also, if this DOES work, well, I have something I can use in the future. "Wheels," you ask, "do you really think you're going to use a gravel washer in the future after these two projects?"
The answer is "That's the other half of the reason for these diversions."

I"m like 70 whole percent certain.

The good news is, it works!

The medium news is, the 10" whole-home filter quickly clogged and choked off the flow into the pump, causing a MASSIVE drop in pressure. So it quickly became ineffective. I tested it by trying it in a clean bucket with and without the filter in the line, and it was virtually unusable with the clogged filter.

The bad news is, the shale hypothesis is probably right. No matter how much I wash it, a fresh spray from the garden hose fills an entire bucket up exactly as much red muddy water as the last time.

So there goes that approach. On the other hand, now I have a proven effective washer I can use on my sand and store-bought gravel (which needs washing anyway), and a transfer pump I've been meaning to get to deal with low-lying areas in wet weather, and a spare filter for the home unit in our crawl space.

headache said:

Since we're leaning into scope creep here- would it be worth adding a settling tank on the return line before the filter, the size of a rolling trash bin or so? Or does it stay suspended too long for that to be a benefit?

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A lot of it is ultra-fine sediment, smaller than household dust. When I left the pipe spray nozzle in the bucket and let it settle overnight, it formed an extremely thin film over the pipe that wipes away easily but has zero perceptible mass or resistance.
From experience with the stuff in my residential well (hence the whole-home filter under the house), settling wouldn't happen quickly enough in a tank with any turbulence.

I thought about buying a less-fine filter (10-20 microns) to stave off clogging, but that probably wouldn't work towards any more success. Especially if there really is mud-rock in the gravel.

Well this gravel isn't for the pond specifically. I was still planning to use Black Diamond blasting media for a dark, sandy look in there. This was for my side-project of setting up an old aquarium, with an under-gravel filter. No sense using a flocculant in that environment.

I've taken a closer look at the gravel, and I think I've spotted the shale. It's in the form of little stone "slivers" that look exactly like the last bits of bar soap: long, tapering, very thin. They're fragile (of course) but they also can be scratched with a fingernail. And my bucket from the landscape supply is full of them.

It's been a roller-coaster for sure.

Anyway, for the side project: aquarium, my DIY light hood is done!



Assembly below the fold!


The finished unit, assembled!


Glad that project is behind me. Now to find something else to overcomplicate! That way the project can never be truly finished, and technically I can never do it badly!

So I decided to hit up Pet Smart and get the largest bag of the cheapest non-epoxy-coated gravel I could find. With a price match from the website, it was just under $1/lb. I spent over 70 dollars buying what I hope will be enough.


Then I got home and took a closer look. The type and size of stone looks suspiciously like the "pea pebbles" I bought from Home Depot in a 48lb. bag for $5. So I brought out my sifted pea pebble stuff from the first run of the gravel sieve and did a little comparison. The stuff that went through my mesh is on the left, the stuff left behind is on the right, and the pet store fish-rocks are in the bag.





The smallest and the very largest stones are different between them, but the overlap is enormous. And it's all the same type of stuff, basically crushed quartz-based river rock.

I could have gone to the hardware store and spent as much money to buy 3x as much gravel for the price of one pet store bag and sifted it myself.

Wheels Of Confusion said:

I could have gone to the hardware store and spent as much money to buy 3x as much gravel for the price of one pet store bag and sifted it myself.

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Well, maybe not. I just did a few more experiments with my hardware store pea pebbles and yield through my sieve is about 12-14% by mass versus the unsifted input.
So in order to get about 75 pounds of gravel I'd have to sift something like 550 pounds of pea pebbles, and it would only save a couple dozen bucks, and take forever.

Anyway, moving on with my aquarium side project build today. I saved from work a piece of translucent-white polyethylene sheet, about 1/2" thick, one side with the impression of many hundreds of die-cutting stampings. I'll face that side upwards towards the tank bottom and put the "clean" side below, showing through the open frame of my iron tank stand.
I'ma prep the surface Krylon it black + clear coat, to protect it from UV and match the stand and the plastic frame of the aquarium, and use it as a footing underneath the tank. It'll raise it up a little, but will also provide a "floor" below the tank to help keep temperatures stable. I've already painted the bottom (outside) of the tank black to keep pesky photosynthetic microbes at bay under the substrate, but this will serve as an additional light barrier as well.



("What about leveling the tank, Wheels?" you ask. I've checked several times and it's already level. Otherwise I'd try to squeeze in a self-leveling foam rubber mat too.)

Once I have this tank set up, I can use it as a kind of "nursery" for plants while building my pond out. Bonus: more tanks means keeping more fish!

I'm gonna have to set up a quarantine tank soon regardless of which destination gets populated first, so I'd better prep one of my old 10-gallon tanks with some heavy-duty filtration and start cycling it.