Originally Posted by patm
Pumilio, just curious how the clay holds up over time. With heavy misting and high humidity, would it naturally clump and become impermiable over time? Also, how do you think the nutrient base would hold up over time? Would this have to be replaced over time, or do you think you could get several good years out of it?
Very informative, thanks for sharing.
Hi guys, interesting thread here. Nice work on the recipe Doug. I look forward to seeing how it holds up over time. Here's an update on the recipes I've used:
- Cheap non-clumping kitty litter - the first clay substrate I used. I have the original tanks set up in 1995 or 1996 still growing strong. The litter simply does not break down and plant growth remains healthy.
- DOB Redart mix (described in the other clay thread). How long has it been now - 4-5 years since I set that up? I have mixed results to report. The clay remains fairly stable but the sand-like aggregate structure has broken down over time. A coupld times of aerated it by poking holes clear through to the drainage layer to keep it draining well. I still like the look of it but there is room for improvement. I'm curious to see how these newer recipes hold up because they sound promising. Also, this mix does not support as much microfauna as kitty litter substrate. I'm pretty sure that is a function of the aggregate breakdown. There just isn't as much surface area between pore spaces. Again, stabilizing that sand-like structure is an important goal. Also, this stuff eats leaf litter rapidly. I actually think that is a good thing so just an observation. I suspect it has more to do with the night crawlers that were added hoping to maintain porosity than the clay itself.
Someone asked if it helps with pumilio. All I can say is that a combination of UVB lighting and calcium supplemented substrate seems to completely eliminate calcium deficiency issues in froglets. It has now been over 10 years since I've seen a case of hypocalcemia and I would guess something like 40 froglets have come out of that viv.
I haven't tested the pH of my substrate but I did test the effluent water that drains out after water has filtered through. One year after putting the substrate in, that pH was running about 8.6 so the substrate was pretty alkaline. I should test it again as I suspect it has dropped due to leaching. I also used slaked lime as the calcium source in mine which, as has been pointed out, is not the best choice since it is so reactive. But I haven't seen any issues and plants root and grow in the substrate just fine.
Overall I would say that early recipe was a step forward but not perfect. Maybe one of these new recipes will prove to be the ultimate clay-based substrate.