# clay fail



## the_deeb (Apr 21, 2008)

I tried incorporating some clay into my paludarium dripwall. I used "Special Kitty" brand litter which I mixed up with hot water, then added about equal parts peat moss and long fibered forest moss, kneaded it and then applied it to a few parts of the background (over ecoweb or drylok-coated GS foam). I let it dry for a day (~20hrs). Last night I turned on the water supply to the drip wall and the clay immediately started washing off the wall (and completely clouding up the water section). If I rub my finger on the clay it easily wipes off.

As a test, I also added some water to the leftover clay mix that I had sitting in a bucket and it quickly broke down and turned back into a slurry.

Is this typical or did I do something wrong? Any suggestions for how to fix this? The cloudy water is unacceptable to me. I'm thinking of brushing on a light coating of epoxy mixed with moss to partially waterproof the clay. What do you think of that?


----------



## shazzbott (Sep 17, 2010)

I personaly used clay in my background i used the blue bag from petsmart calle doctor e somtings litter, and it worked well I put it right on the glass that might be your problem, but i have heard it works on top of gs. Also I never let mine dry out just because there was no need so those might be your problem I would guess its the litter though some brand are very unstable.


----------



## Ed (Sep 19, 2004)

Yes, your flow rate was too high and the structure needed to hold the clay together doesn't exist yet. 

When you start with a powdered clay product, there isn't any structure or adhesion between the particles to allow it to resist the water flow. Leave the water off for a couple of days to let it stabilize a little again and then turn the water on the lowest possible rate. You will get a little loss of clay but after a few days, biofilm will start to form and stabilize the clay. The greater you allow this to stabilize the wall the better the clay will resist water flow. As the film gets established you can turn up the flow rate until the full flow is established. 

Ed


----------



## the_deeb (Apr 21, 2008)

Just wanted to update this to say that, as usual, Ed was right. I gave the clay a few days to set up during which I ran the dripwall at a low rate for only couple of minutes at a time, a few times a day. After about a week I turned the dripwall on for real and it's been running since. It's only been a few days, but so far the clay seems to be holding up fine and the water running off of it is clear. Whenever I disturb the clay (eg. pushing in a plant) the water clouds up for a little while but clears up again within about 10 mins.

Thanks Ed!


----------



## Ed (Sep 19, 2004)

Your braver than me, I would have turned the flow rate up much more slowly.. 

Ed


----------



## Judy S (Aug 29, 2010)

Your explanation of your method of a drip wall over the clay finally became clear to me after having read many of your comments in these threads...thanks for the simplest explanation...or did the lightbulb just get turned up in my head??


----------



## the_deeb (Apr 21, 2008)

Ed said:


> Your braver than me, I would have turned the flow rate up much more slowly..
> 
> Ed


I still don't have it running at it's full potential flow yet, though admittedly my ball valves don't allow me as much control as I'd hoped. The problem is that my PVC spray bars direct their water backwards into the ecoweb layer, from which the water runs down onto the clay sections. If I reduce the flow too much there isn't enough pressure for the water to go into the ecoweb and instead it drips directly from the spray bar pipes onto the clay. Even though the flow rate was lower, I felt like the drops landing directly on the clay would cause more erosion than the higher flow rate running evenly over the clay as it streamed out of the ecoweb. 

In any case, I pretty much turned on the dripwall for a little while at a time and watched the water run off to see how cloudy it was. Once the run off from the clay started to look pretty clear I decided I'd turn on the water flow for longer. 

Judy - I'm not sure if your comment was directed at me or Ed, but either way I'm glad you figured it out


----------



## Okapi (Oct 12, 2007)

If you could get some moss or even algae growing on the clay you should be able to keep it together. My clay background tank pretty much repels water now. One section where it touches the water feature wicks up water has a slimy layer of algae growing on it. The top and middle has some sort of light green biofilm (not sure if it is algae or bacteria). The rest of the clay took on a darker brown biofilm which spread outwards from the strands of java moss that I laid on the clay when it was first set up. When I first started to spray the clay with distilled water, the water would wash small sections off and cloud the water feature. Now each different colored section repels water differently. The algae parts tend to soak water up then slowly release it when sprayed. The light green parts are almost like wax and completely repel the water, causing it to bead up and run down the clay. The brown parts dont make the water bead up and fall off like the light green, but they dont soak it up either. The water just runs across the surface evenly without picking up clay particles.
It took a couple weeks with twice daily mistings and high humidity to produce the biofilms.

You can see the tank in my signature.


----------



## Ed (Sep 19, 2004)

the_deeb said:


> I still don't have it running at it's full potential flow yet, though admittedly my ball valves don't allow me as much control as I'd hoped. The problem is that my PVC spray bars direct their water backwards into the ecoweb layer, from which the water runs down onto the clay sections. If I reduce the flow too much there isn't enough pressure for the water to go into the ecoweb and instead it drips directly from the spray bar pipes onto the clay. Even though the flow rate was lower, I felt like the drops landing directly on the clay would cause more erosion than the higher flow rate running evenly over the clay as it streamed out of the ecoweb.
> 
> In any case, I pretty much turned on the dripwall for a little while at a time and watched the water run off to see how cloudy it was. Once the run off from the clay started to look pretty clear I decided I'd turn on the water flow for longer.
> 
> Judy - I'm not sure if your comment was directed at me or Ed, but either way I'm glad you figured it out


That is a problem with ball valves. Keep an eye on your drip flow as over time, you may have to reset the opening in the drip valve. Once the wall is well established you may also have to really open the valve to flush out the drip system as things often grow in it. My main problem is with a moss that grows in the holes for the droplets and then seals them off. 

You may also find that your plants don't like it as much with it constantly flowing or that it doesn't need to be on, all of the time to keep the humidity up or get great plant growth. My dripwalls are only one for a short period of the day now.. 

Ed


----------



## the_deeb (Apr 21, 2008)

An unfortunate 45 day update: I can safely say that my clay dripwall experiment hasn't worked out too well in my tank. Things seemed to be going pretty well - I had a nice thick biofilm develop on top of the clay and the water seemed to be running smoothly down it. However, after cleaning my filters a few days ago it seems that the rate of water running down the wall increased a bit. I came hope yesterday to find that a big chunk of the clay had slid right off the wall. The biofilm was still still holding the chunk together, but it looked like the biofilm-enforced surface had separated from the underlying clay. I tried to adjust some of the existing clay to cover up the hole, which caused an even larger section of clay to destablize and fall off the wall. 

Overall, I've concluded that the kitty litter clay mix works very well in areas that are wet, but not under direct flow. The biofilm definitely helps to stabilize the surface of clay, but under high levels of flow the underlying clay remains unstable and is easily washed off vertical surfaces in response to minor disturbances or changes in the flow rate.

Keep in mind, the amount of flow I have in my paludarium is much higher than what you'd find in the typical frog viv, so this may not be as much of an issue for others. Also, Ed's clay mix may hold up to the water better than my kitty litter mix.


----------



## koolparrot (Dec 31, 2010)

I used the Generitic Petsmart kitty litter unsented is working good for me but i dont have a drip wall but if you mix in some moss it holds up really well.


----------



## Dendroguy (Dec 4, 2010)

i mixed in cocoa fiber and sphagnum moss and it held up really well although i had to put small stones where it accually falls to prevent erosion


----------



## btcope (Jan 7, 2009)

i had a couple of "shelves" that persistently did not want to stick to the wall. I've found that clay, not unlike concrete, doesn't do well in shear tension. from here i decided to make "reinforced" clay walls ... i.e. stick a bunch of toothpicks into it in the areas where you're having trouble ... then just mush some clay over the pointy end so they don't stick out sharp and poke anybody.

hope this helps,
brett


----------

