Vermiculite at the Bottom of the Pot

MaryJaneAdvocate

Active Member
While I was planning my grow, I noticed a guy used vermiculite mixed with perlite in the bottom of his pots when he grows. At the time I thought that would be a great idea! There would be that inch or two in the bottom with water retention and it would be all good and dandy... now 5 weeks into my grow I am starting to think that was a bad idea. I poured about a half a gallon of water into the 3 gallon pots and no water comes out of the bottom... So then I start to think, what about flush time? All my salts from the nutes are going to build up in that vermiculite and it may pose difficult down the line to flush them out.

What do you guys think?
 

new2420grow

Active Member
I put a layer of Perlite at the bottom. Just Perlite, to help with draining. From what I understand, vermiculite holds water.
 

cdnbudder

Active Member
I'd stick to just perlite for drainage...but only half a gallon into a 3 gallon probably won't get you much runoff anyway depending on the size of the plants. My 3 gallon pots take about a full gallon before runoff
 

harris hawk

Well-Known Member
mix vermiculite with soil after you have already mixed the soil and perlite and then put medium size rocks or broken clay pot (small pieces) in bottom of growing pot and also . make sure you have drain holes in bottom of your container then fill your containers whit you mix of soil (75%) perlite (20%) Verm (5%)
 

vostok

Well-Known Member
True, vermiculite holds water and perlite sheds it, best to avoid the cat litter(vermiculite) and mix 30-50% perlite into your soil, and an aid to avoiding compaction and as an attempt to avoid any nute burn, is used to dilute 'hot' soils
 

BWG707

Well-Known Member
If its not too difficult I would at least think about transplanting. Good drainage is extremely important. Root rot/slime may not show up right away, but I'd hate to see it during flowering.
 

AimAim

Well-Known Member
What do you guys think?
I think if you want to flush it just keep adding water, it's gotta come out. I use about 35% perlite and get a bit of runoff in a 5 gal pot watering with 1/2 gal. As mentioned vermiculite soaks up water and gets soggy.
 

MaryJaneAdvocate

Active Member
I know the differences in vermiculite and perlite, but thanks for the info guys. I won't be using vermiculite in any other grows lol, and The soil on top of the vermiculite is 50/50 perlite/Happy Frog soil. Honestly it should be a really good soil for drainage, but that vermiculite is keeping in all the moisture at the bottom. My drainage holes on the bottom of the pot are pretty good and I stuck my finger up in there to make sure the vermiculite isn't clogging the hole, but still no water runoff. Hopefully the salt buildup will not be too bad. I think I am going to flush extra the last couple weeks to try and push water through that damn retention layer! I am so peeved that I put that layer of vermiculite down there. I am halfway through week 5 and believe it is much to late to transplant BWG.

Next time I am doing the pebble bottom layer so I know I can have some drainage. I am just kinda sketched out that I don't have any runoff o_O
 

MaryJaneAdvocate

Active Member
Bigger pieces than perlite but it would probably do the job of draining well. Hmmm starting to think I should put hydroton on the bottom of the pot!
 

bwest

Well-Known Member
I know the differences in vermiculite and perlite, but thanks for the info guys. I won't be using vermiculite in any other grows lol, and The soil on top of the vermiculite is 50/50 perlite/Happy Frog soil. Honestly it should be a really good soil for drainage, but that vermiculite is keeping in all the moisture at the bottom. My drainage holes on the bottom of the pot are pretty good and I stuck my finger up in there to make sure the vermiculite isn't clogging the hole, but still no water runoff. Hopefully the salt buildup will not be too bad. I think I am going to flush extra the last couple weeks to try and push water through that damn retention layer! I am so peeved that I put that layer of vermiculite down there. I am halfway through week 5 and believe it is much to late to transplant BWG.

Next time I am doing the pebble bottom layer so I know I can have some drainage. I am just kinda sketched out that I don't have any runoff o_O
I grow in 3 gallon bags, and no way would I have runoff on just a half gallon of water. The vermiculite holds water, but won't keep water from running out drain holes.
 

LIBERTYCHICKEN

Well-Known Member
when I start seedlings I put some pearlite in the bottom , In hopes that if the plant starts to go rootbound that the roots will mostly stay in the dirt (with light waterings)

I start a lot of seedlings and dont always have time to transplant when I should

It seems to help
 

Nutes and Nugs

Well-Known Member
I put a layer of limestone in the bottom of my pots.
Hopeful thinking buffers the ph of the water drawn up through the bottom of my 'hempy buckets'.

I never top feed my plants.
Passive hydroponics is dandy.

There is some red lava rocks mixed in the limestone here.

bottom mix.JPG

Easy watering.

passive2.JPG
 

MaryJaneAdvocate

Active Member
Hmmmm, interesting. I've never done any research on this method. Seems interesting though, hey what's the fun in it if you don't try new stuff though right?
 

cwlorentz

Member
The Peat in your upper layer will probably hold at least a .5 gallon of water The vermeculite absorbs H2O but only to a point. I water to the point of just starting runoff at least 1 out of every 2-3 waterings. Test your soil H2O retention by placing 1 gallon of your upper soil mix in 1.5 gallon pail with no drainage. Pour 1/2 gallon H2O in pail, stir this sloppy mess gently, cover pail tightly to avoid evaporation, wait 24 hours stir if neccessary. Pour H2O out of pail and measure. You now have the retention rate of your soil. If all H2O is absorbed you are seriously under watering, you are only watering the top of the soil, your deep roots are possibly dry. Your flush should not present a problem if you flush with 5 gallons straight H2O then 2.5 gallons PH'd nuted water over a period of 6-12 hours.
 

Nutes and Nugs

Well-Known Member
The Peat in your upper layer will probably hold at least a .5 gallon of water The vermeculite absorbs H2O but only to a point. I water to the point of just starting runoff at least 1 out of every 2-3 waterings. Test your soil H2O retention by placing 1 gallon of your upper soil mix in 1.5 gallon pail with no drainage. Pour 1/2 gallon H2O in pail, stir this sloppy mess gently, cover pail tightly to avoid evaporation, wait 24 hours stir if neccessary. Pour H2O out of pail and measure. You now have the retention rate of your soil. If all H2O is absorbed you are seriously under watering, you are only watering the top of the soil, your deep roots are possibly dry. Your flush should not present a problem if you flush with 5 gallons straight H2O then 2.5 gallons PH'd nuted water over a period of 6-12 hours.
What a pain in the ass.

Mix your soil.
PH your water.
Feed from the bottom and pay attention to your leafs.
They will tell you if you need to add anything.

I only give nutes to my plants every 2 weeks.
Plain water inbetween.
Good soil will do the rest.
 

MaryJaneAdvocate

Active Member
Yea it seems like I only need to water at most twice a week... seriously. I am lucky if I water it twice a week. I feel the bottom layer every few days up through the drainage holes and it stays moist.
 

Lysemith, Lowkey

Well-Known Member
Vermiculite has a high negative (?) cation potential, which holds the correct charge to water with nutrients and balance out, it creates a kind of battery with the plant and produces abundant growth, the only problem is it holds water like a motherfucker. creates rot and shit, problems with drainage like everyone has said.

I think with net pots if you were to mix this with maybe 30% vermiculite and soil, pack this around the edges of the net pot and put perlite at the bottom so that the verges of the air-pots would hold a little more water and it would drain well straight through the center. - I have not tried this, I just think it makes a lot of sense.
 

Nitegazer

Well-Known Member
I may take some criticism for saying this, but it is a myth that rocks, perlite or any other stuff at the bottom of the pot improves drainage. Putting stuff in the bottom of the pot only reduces the amount of space for your roots. Rocks or perlite do not suck the water out of soil-- the soil will continue to hold just as much water regardless of the material under it. In fact, changing mediums within the pot only slows water movement.

http://puyallup.wsu.edu/~linda chalker-scott/Horticultural Myths_files/Myths/Container drainage.pdf
 
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