Unsolved mystery: UGF exposed

[Gideyon]

I've been doing an experiment with anoxic filtration utilizing a penplax undergravel filter. 

I have the UGF on the glass, then a fine mesh nylon fabric on top of that, then a baked clay, then gravel. 

Something strange happened here and I can't figure out what. 

 

It looks like the fabric lifted, exposing the plate.  Some of the clay mush started falling in too.  

I have no living things in this tank other than bacteria. 

The uplift tube is on the other end of this 10 gallon. Could air from the airstone somehow gotten trapped under the UGF, and exploded out the far end? 

Edited December 27, 2021 by Gideyon

[Odd Duck]

Sorry you haven’t gotten any replies so far, but I suspect that like me, it’s a situation where nothing specific comes that could have caused this other than what you’ve already speculated.  As the day goes on, someone might have some other ideas.  For me . . . . 🤷🏻‍♀️ 

[Tanked]

Unless it is possible that you never noticed the upturned fabric earlier, a gas bubble is the best guess.  The 3 pieces of clay lodged higher up in the gravel, and the general conical shape would tend to support that theory. 

If the aquarium is out of level in either direction, or if the substrate is thinner at this point, you may see the bubble forming and get to witness the burping at some point in the future.

[Gideyon]

On 12/27/2021 at 10:00 AM, Tanked said:

Unless it is possible that you never noticed the upturned fabric earlier, a gas bubble is the best guess.  The 3 pieces of clay lodged higher up in the gravel, and the general conical shape would tend to support that theory. 

If the aquarium is out of level in either direction, or if the substrate is thinner at this point, you may see the bubble forming and get to witness the burping at some point in the future.

I'm pretty sure I would've noticed this when I laid down the gravel.  I remember thinking I didn't like the uneven clay layer but it was too difficult to fix.  So I would've certainly noticed the blue plate exposed.  

It is a little sloped.  The thinner side is what you see. It elevates slightly to the uplift side. Not intentional, but I didn't think it would matter after I realized it.

What gas would form under the plate?   The goal of this experiment is for nitrogen to be formed from nitrates. I did notice a drop in nitrates and suddenly the drop stopped dropping.  I wonder if this "burp" is related. 

 

[lefty o]

i would venture a guess that an air pocket found its way out there.

[Tanked]

I'm neither a chemist nor a biologist, so I can't begin to guess what gases form when things decompose..  As you already mentioned, it could be just trapped air from the air stone.  I find it interesting that it found a weak point and built enough pressure to lift the fabric.

[Gideyon]

I'm going to try and even out the gravel.   After I figure out how to put this back without tearing part of it down. 

 

Thanks for the feedback.  The air pocket or gas bubble makes sense as this is the thinner side.   Maybe more even a layer would help prevent it.    

[Gator]

@Gideyon and @Tanked; the gas bubble could very well be a pocket of methane, AKA swamp gas, caused by the decomposition of any organic matter in the clay, but as @Tankedsaid, it could just be an air pocket, vacuum your gravel and wait to see if it comes back.

[Gideyon]

On 12/27/2021 at 11:26 AM, Gator said:

@Gideyon and @Tanked; the gas bubble could very well be a pocket of methane, AKA swamp gas, caused by the decomposition of any organic matter in the clay, but as @Tankedsaid, it could just be an air pocket, vacuum your gravel and wait to see if it comes back.

No organic matter.  Nothing living or dead in the tank other than bacteria. 

I'm going to go with air pocket. 

[mountaintoppufferkeeper]

Late to this party but I say a gas pocket that could not permeate through the nylon is the only thing I can think of that would cause that lift. Do you expect the anoxic layer would be limited to below the nylon as a result of it holding that air bubble below the clay and gravel? 

[Gator]

@Gideyon; OK, but still vacuuming the gravel should get rid of the bubble for now, removing the mesh may ensure that the bubble doesn't form again.

[Gator]

@mountaintoppufferkeeper; If you're in the Sierra Nevada's, the Cascades, or the Rockies, I'm on the fence about all of that snow you're getting. On the one hand, I know that 10 fee4t of snow used to be normal for those mountains, but it's been a very long time. The snow will go a long way to ending the drought and refill lakes, but on the other hand, if it melts too fast, all of that water will runoff too fast and cause flooding and not soak into the ground deep enough to ease the drought for very long, not good. I'm hoping for the best. 

[mountaintoppufferkeeper]

On 12/27/2021 at 10:38 AM, Gator said:

@mountaintoppufferkeeper; If you're in the Sierra Nevada's, the Cascades, or the Rockies, I'm on the fence about all of that snow you're getting. On the one hand, I know that 10 fee4t of snow used to be normal for those mountains, but it's been a very long time. The snow will go a long way to ending the drought and refill lakes, but on the other hand, if it melts too fast, all of that water will runoff too fast and cause flooding and not soak into the ground deep enough to ease the drought for very long, not good. I'm hoping for the best. 

Rockies for me an hour west of Colorado Springs and little over  9100 feet up. Nothing really here so far minus a good wind storm and a few quick 2-4" hits. Most I've had here is 3' in a night and -22 Fahrenheit for a low temp..... but the daphnia do return to the tub every summer 

[Gator]

@mountaintoppufferkeeper; The highest elevation I've ever been and walking around on was 9100 feet somewhere along I-80 in WY., at least that's what the sign said. Being born and raised at sea level around the world, I was expecting a serious level of altitude sickness, dizziness, or shortness of breath, but neither happened, I was able to walk up a small hill to take a better photo of the beautiful valley below. The most snow I've ever seen come down at one time was here in 2011 when we got 28 inches in 12 hours, the coldest temp I've ever been in was here in 1985 when the temp was -22 F with a wind chill factor of -70 F, my moustache froze more each time I exhaled, and the only time I've ever seen Diamond snow (or dust) was here in 1976. That was fantastic, the temp was -15 F, no wind, not a cloud in the sky, the sun was shining brightly, and it looked like all of these diamond crystals were falling out of the air. I'll give it the same wording I used each of the three times I've seen the Grand Canyon, WOW!

Speaking of canyons, someday, I'd love to see the Black Canyon of the Gunnison. It would be fantastic to be at the top looking down to the bottom of a canyon that is a mile deep, but only 40 feet across at the top. I may never see it, but I'll say it anyway, WOW! 

[dasaltemelosguy]

Yeah, WOW says it all! -70*!  I can't imagine!  -20* was the coldest I've experienced. I can just picture the sky and crystals you speak of. The clarity at those altitudes adds a drama and contrast that is breathtaking. 

Speaking of which, I got so sick in the Sierras. I flew in from NYC, went straight to Mount Whitney (14,000') and got to about 10,000' and barely made it back down and spent all night sick in a motel. Classic beginner's mistake! No acclimation is bad for everything!

Still, I love the mountains. I used to climb when I was young. The highest I ever got without mechanical or pharmacological aid😎 was 18,000' on Denali. Amazing vertical relief. Looking down was like stepping out of an airplane. The tallest vertical rise on earth.

I believe the greatest rise from base to summit in the Himal is 13,000', Kanchenjunga. But the mountains start the rise from an 18,000' plain so they're actually higher, but not as tall.

Denali and several peaks in Alaska and Canada are taller but not as high. Although 'only' 18,000'-20,000' high, they rise from only 1500' plain, so a full 18,000' wall of rock and ice stand before you.

The rise is jaw dropping. Mount Saint Elias rises to 18,000' only 10 miles from the ocean! On the rare clear day, you can easily watch the summit from the boat.

Although there's peaks all over the West that stand out similarly like the Tetons and Yosemite. 

Still, I feel nothing compares with Grand Canyon. It is to me, simply incomprehensible and possibly not photographable. Or even Niagara Falls, how to convey that immense size and power in a photograph (setting aside the carnival atmosphere they've built around them)?

I was a photographer long ago and did shoots in all 50 states. I have always failed in trying to capture Grand Canyon. I came to wonder if it's so vast and foreign to human experience, if it is not representable in photographs. And so otherworldly, I'm not sure a camera can convey the experience.

Or at least, I failed to capture it.  I recorded it, but I can't convey it. 

I hope I'm not boring everyone but only miles from LA is Cucamonga Peak. It's part of a midlevel range that is less than exciting but for an area of about 6 miles, the foothills vanish, and the mountain is very steep such that it towers some 8000' over the city (1000') and has an altitude of about 9000'. Smaller, but the same vertical rise as Grand Teton so it can be very dramatic. 

I took this on a rare day we had snow as low as 4000':

Love Black Canyon too!

Edited May 27, 2023 by dasaltemelosguy

[Gator]

@dasaltemelosguy; It's impossible to capture the grandeur of the Grand Canyon in a photo. I first saw the Grand Canyon when I was 9, again when I was 18, the 3rd and final time when I was 45, I'm really glad that I got to see it.

 

[Odd Duck]

On 12/27/2021 at 9:36 AM, Gideyon said:

I'm going to try and even out the gravel.   After I figure out how to put this back without tearing part of it down. 

 

Thanks for the feedback.  The air pocket or gas bubble makes sense as this is the thinner side.   Maybe more even a layer would help prevent it.    

If you have one of those aquascaping rakes/levelers I would try that since it’s thin and can slide right down the side of the tank.  If you don’t have one, then I would try a thin putty knife or scraper.  Even a thin, flexible, but somewhat dull, butter knife might work to catch the fabric and push it back down.

[gardenman]

The Penn Plax UG filters (at least the ones I'm using) have a grate at the bottom of the uplift tubes so it would be hard for an air stone to "leak" air to cause the bubble unless you've got a very powerful air supply. Moving the air stone higher up in the uplift tubes would help eliminate even that possibility. They come with a little rubber washer around the rigid air tubing that lets you put the air stone wherever you want it. If you were pumping in more air than the tube could expel it could have backed up under the grid and burped out where you have the issue. Some water supplies have a lot of dissolved gas in the water also. You'll often notice bubbles on everything in the tank after a water change. Those same bubbles would form under the UG grid, and the fabric layer could have prevented them from gently bubbling out. After a few water changes enough could have formed to have lifted the fabric and force their way out.

[Gator]

@Gideyon; I don't know how well this will work for you, but try Powerheads, these should keep the air pockets at bay.

[Gideyon]

On 12/28/2021 at 10:06 AM, Gator said:

@Gideyon; I don't know how well this will work for you, but try Powerheads, these should keep the air pockets at bay.

How so?  I do have one but it's too powerful for a 10g. I only use it to pump water in and out of the tank. 

Would an HOB have the same effect?   I switched mine off and now only using a sponge to save power.  I didn't have this problem before the switch (and it was running for many weeks). 

[Gator]

You're right, a Power Head may be too powerful for a 10 G tank. I bought two Power Heads almost three years ago with the intention of turning a 29 G tank with a canister filter into a 29 G tank with an UGF, but after getting everything together to make the switch, I decided that I really do like the look of live plants in my tanks. The reason I know that it was almost three years ago when I bought these is that when I opened one box to read the instructions to see if it can be used to change water (mine can't), I found the sales receipt dated 3-21-19.

Yeah, using the HOB would definitely help matters, you could grow live plants again.

 

Edited December 29, 2021 by Gator

[Gideyon]

I'm curious... What is it about an HOB/powerhead that could prevent airpockets?