it's not whether or not you have fines, it's just that you can't count the fines as "drainage΅. So if you want say, 30% of your mix to be calcined DE chunks, that means 30% without the fines.
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Perlite and beyond: the pros and cons of various drainage and aeration amendments
- Thread starter mad librettist
- Start date
Wiki puts perlite at 12-15% Al2O2 compared to 2-4% alumina, comprised mainly of clay minerals, for DE.
I think the main concern was in the size of the fines and their influence on the water table. If the DE is coated, it's less effective as well.
While the pH is a little high, a quick Google search tells it is pretty mild.
I like to think that the noncrystalline silica, the cal/mag, and other trace minerals are benefiting the soil and are available to the plant. Can't sat they are. The safe bet is to screen them out and use known methods or you can play...
In reply to the question on Moltens DE. I believe that is what I've been getting at Auto Zone. No problem.
I think the main concern was in the size of the fines and their influence on the water table. If the DE is coated, it's less effective as well.
While the pH is a little high, a quick Google search tells it is pretty mild.
I like to think that the noncrystalline silica, the cal/mag, and other trace minerals are benefiting the soil and are available to the plant. Can't sat they are. The safe bet is to screen them out and use known methods or you can play...
In reply to the question on Moltens DE. I believe that is what I've been getting at Auto Zone. No problem.
I can attest to the fizzing being a sign of weakness. Just these last few weeks the chunks of DE (kitty litter) have been breaking up before my eyes as i water (with a sprayer wand).
I also have a bit of a ph problem due to a (definately) unnecessary handfull of dolomite when i recycled my medium. Compound this with the higher ph from the kitty litter and that would explain my pale yellow, droopy new leaves on my girls in bigger pots...
We live and learn. Letting it dry out helps. Definately easier to overwater too.
O well. I invested in a 100 litre bag of perlite today. I cannot buy pumice, crushed lavarock or the turface stuff around here. I can get bags of horticultural DE but its $10 more for 4 times as much perlite... also the perlite is certified as acceptable for organic certification so its safe to use right...?
Think im gonna make me some big batches of biochar and also get some pure silica propagating sand which is available here by the ton for my outdoors this season. If i like it then i will use the sand indoors too.
I also have a bit of a ph problem due to a (definately) unnecessary handfull of dolomite when i recycled my medium. Compound this with the higher ph from the kitty litter and that would explain my pale yellow, droopy new leaves on my girls in bigger pots...
We live and learn. Letting it dry out helps. Definately easier to overwater too.
O well. I invested in a 100 litre bag of perlite today. I cannot buy pumice, crushed lavarock or the turface stuff around here. I can get bags of horticultural DE but its $10 more for 4 times as much perlite... also the perlite is certified as acceptable for organic certification so its safe to use right...?
Think im gonna make me some big batches of biochar and also get some pure silica propagating sand which is available here by the ton for my outdoors this season. If i like it then i will use the sand indoors too.
the DE is definitely more expensive, and you don't want to use the wrong stuff.
If initial cost is a big issue, DE/Turface is not a good choice.
However, if you are running no-till, it is cheaper in the long run.
If initial cost is a big issue, DE/Turface is not a good choice.
However, if you are running no-till, it is cheaper in the long run.
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SeaMaiden
Thank you for the answers. Now how about some information helping me to understand what is perched water table is when growing in a container environment? Google isn't exactly helping me out with this one very well. Just a link would be sufficient.
check the last link in my sig, it leads to many videos explaining media.
perched water happens when the forces holding water on to the medium particles is stronger than gravity's pull on the water. The higher up you travel, the more the water wants to drain. The point at which both forces reach equilibrium is the perched water table.
The perched water table height is a property of the medium, not the container. So drainage holes don't help. Tilting the pot can help, because it pushes some of the water higher, which overcomes the forces holding it up. Taller containers also drain better than shorter containers of the same volume, because more of the medium is higher up the pot where gravity holds more sway.
this image shows what happens with the same medium over different container sizes with identical proportions. However if you compared the first container to an imaginary 2" pvc pipe long enough to match its volume and packed with the same medium, a smaller portion of the total medium would be under the perched water table height. However the actual perched water table height is unchanged.
I actually could give two shits about perched water. I use living mulches to deal with that.
perched water happens when the forces holding water on to the medium particles is stronger than gravity's pull on the water. The higher up you travel, the more the water wants to drain. The point at which both forces reach equilibrium is the perched water table.
The perched water table height is a property of the medium, not the container. So drainage holes don't help. Tilting the pot can help, because it pushes some of the water higher, which overcomes the forces holding it up. Taller containers also drain better than shorter containers of the same volume, because more of the medium is higher up the pot where gravity holds more sway.
this image shows what happens with the same medium over different container sizes with identical proportions. However if you compared the first container to an imaginary 2" pvc pipe long enough to match its volume and packed with the same medium, a smaller portion of the total medium would be under the perched water table height. However the actual perched water table height is unchanged.
I actually could give two shits about perched water. I use living mulches to deal with that.
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SeaMaiden
How do you sort out where that point is? Thanks for taking the time to answer, everything I'm reading on Google is talking about aquifers.
the forces and physical properties involved are identical!
a "dumb" way to determine pwt height is to stick a toothpick into the side of the container after watering and waiting for it to drain (no tipping). Start at halfway from the top and keep inserting it progressively lower until water drips out.
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SeaMaiden
I'm sorry, mad. If you will take a moment to note the posting times you will see that we posted pretty much on top of each other. That means I did not see your post which manage to come up immediately previous to mine. Unfortunately, at this very same time as this is transpiring I discovered that my mother had been attacked by a rescue dog belonging to one of my sisters. Along with all of that, I am, unfortunately, religated to the couch do to my knee injuries for which I still await surgery, and since my husband was so kind as to buy me a Vizio Tablet that's what I'm sitting here using. It presents a hell of a learning curve for me and so I do make mistakes and windows jump back and forth.
I say all this in the hope that I may demonstrate that I am not that dense. Your post that came up one minute before mine explains the concept very well.
Perhaps I am that dense, but I'm trying.
I say all this in the hope that I may demonstrate that I am not that dense. Your post that came up one minute before mine explains the concept very well.
Perhaps I am that dense, but I'm trying.
that sucks about your mom! I hope this doesn't turn her off rescues
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SeaMaiden
Thanks, and I honestly don't know if my sister will try another one just yet. My mom is fortunate that she didn't need stitches, but it's still pretty bad. She refuses to give up her trip to Cabo, though. 72yo, and she keeps on truckin'.
wisco61
Member
figures , guess where I live
http://www.griffins.com/home/about.asp
is listed as a distributor for PBH rice hulls which my hydro store has at $15 for 5 cu ft.
Maybe there is one close to you.
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SeaMaiden
That's outrageous! I pay $8/8'cu! Last time it was on sale, so I paid $6/8'cu. It's not very heavy, just bulky.
Silver's post has caused me some concern. I've been advocating DE without much clarification. Being a mined product, it will vary in quality. Different mines or even different sections of the same mine produce different products.
I'm using Molton #8818 mined in Nevada. With that about 10% of the mix is DE along with rice hulls, pumice, and even a little perlite. I don't use lime. At that and even when trying a larger % of DE, I haven't had the same issues.
I'm using Molton #8818 mined in Nevada. With that about 10% of the mix is DE along with rice hulls, pumice, and even a little perlite. I don't use lime. At that and even when trying a larger % of DE, I haven't had the same issues.
Holmes Slice
Member
I've been using the Burn1/Organics for Beg. recipe for about 2 years now. Also been recycling with a variant of the 3LBs method since I started. I've noticed that after about 3-4 'rotations' the humus buildup makes my mix quite wet and soggy. Adding more peat and more perlite doesn't seem to help. I generally wind up dumping it in the garden, but not after it's ruined a grow in my perpetual scrog due to lockout/water retention and I have to sort of 'reset' with new clones, etc.
I am a brewer and have access to rice hulls and thinking about using them. Should I replace about 50% by volume of my perlite with it on future recycles? Or is it normal to have to discard a bin of soil every now and again? I never have any nutrient issues with Burn1 soil mix and using guano teas. The reliably produce very healthy plants. But every year or so, I lose a crop to this and I am pretty sure it's because the perlite is done for any my mix winds up like a compacted peat bog.
Any ideas?
I am a brewer and have access to rice hulls and thinking about using them. Should I replace about 50% by volume of my perlite with it on future recycles? Or is it normal to have to discard a bin of soil every now and again? I never have any nutrient issues with Burn1 soil mix and using guano teas. The reliably produce very healthy plants. But every year or so, I lose a crop to this and I am pretty sure it's because the perlite is done for any my mix winds up like a compacted peat bog.
Any ideas?
You might want to upgrade your humic source. I found the same with some store bought ewc, it's a texture thing. Once i made my own....problem solved.....best of luck.......scrappy
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SeaMaiden
If it were me, I would drop the perlite completely, then I would add back some sand (if you're concerned about using calcareous vs silicate, just pour a little vinegar on it -- fizzing means it's calcareous), starting at around 25% by volume, and would use the same amount for the hulls.
