For Sr

[Jon Clobert]

A good thread here which has been on my bookmarks for a while now.

^BUMP

E2A stoned me didn't realise it was pinned

Edited September 12, 2011 by Jon Clobert

[christopher99]

Thanks for sharing this information, it is helpful for me...

[tangill]

Hmm a bit of compost science myth and magic, ramblings for sr to take to bits and play with.

The advise going back over a hundred years, was to crock pots to improve drainage and stop compost seeping out of the pots and keep worms out. All has proved to be totally wrong.

Especially with the advent of capillary beds or matting. What you really want is the same medium going from the top to the base of the pot so its capillary profile constant without a break. If you want to change the water/air/drainage capacity of a medium it is best to change the whole medium.

For the most healthy root profile, it is best to water with a fine rose over the entire the compost surface untill you get run through, this oxygenates the water/feed when applied, it also drives stale and toxic gasses down through the rootball drawing in fresh air as it drains down from saturated to its natural holding capacity.

It has been found that crocking pots rather than helping drainage to the surface a pot is standing on, in fact it inhibits it. This means whatever potting medium you use holds more water and less air than its natural capacity, the thicker the crocking level the worse the problem.

The best growing results come from a wet dry cycle, by dry I mean down to 5 or 6% of the composts wet capacity, if you go much lower than that the root ball will shrink away from the pot walls killing a large percentage of the fine feeder roots, you don’t want to do this as it sets the plant back and every time you do it, it will reduce the final yield a bit more. Another problem where a rootball is allowed to dry out to the shrinkage stage is that it is very hard to wet it properly again, What happens is the water runs off the surface and down the gap round the pot edges leaving 70% of the rootball dry.

If your plants are on a sand/matting bed providing there is no crocking the odd over dry rootball will fully rehydrate its self from the bed after the area has been watered.

It is not a good idea to water or feed from a capillary bed unless you have a very very open medium, if you are going to do this you might as well grow hydro.

Where the myth about needing 30 to 70% perlite in compost an an ideal medium for growing cannabis came from:-

In the early days of cannabis growing in the states, the heads growing indoors did not have a clue about gardening or horticulture at all. They wanted to grow plants like outdoors, big plants, so they would use a big pot 10 to 50 gallons fill it with a couple of bags of Schultz container compost, water, sow a few seeds.

Now we all know what happens to 10 gallons of saturated compost in an enclosed container, with no roots to pump the water out and just a little surface evaporation, within a couple of weeks the whole mess goes anaerobic and sour. To compound the problem, the surface dries so they keep watering the seedlings that in turn get sicker and sicker as root fungus get a grip in what is now an ideal environment for it.

Did they look at what the plant industry did? No they were growing cannabis they had to resolve the problem, they stuck with big pots. One method was to fill the pot and just use a tiny amount of water around the seed. Of course this meant watering several times a day as the surrounding compost sucked up the water. Then they tried adding more and more drainage! Grit, sharp sand and finally perlite. Until the 10 gallon pot was only holding 3 or 4 gallons of compost and the rest was inert filler ie they were nearly growing with just water and nutrients. They never learnt about standard potting on techniques or considered them irrelevant or too time consuming.

Even today 40 years on, where large pots and huge plants are no longer the thing. Then the firm belief was that for optimum yield you should not grow more than one cannabis plant under a 1kw light, no one even thinks about that now, its laughable.

Yet we still see people adding large amounts of inert perlite and vermiculite to compost. It just goes to show what a tough plant cannabis is, as it often survives and crops despite the things that are done to it. Its not done any where else in the horticultural industry. So why oh why, when its a completely groundless bit of nonsense does it still hang on in the cannabis world.

this is the best info ive read so far ,thank you very very much OT.DIAMOND

[Cody Cotyledon]

Killer thread. Very enlightening to a soil grower like myself !!

[Cody Cotyledon]

Hi MP, just jumping in cos it's fish-related but I think you've got it the wrong way round there - I also have aquariums and it is the beneficial aerobic bacteria that drive the nitrogen cycle, they live in the greatest numbers in the filter media which is why it needs to be kept oxygenated at all times.

The anaerobic bacteria are the bad guys in the aquarium, they create poisonous by-products by their action once they establish themselves, which is why if you have sand or gravel as a substrate you need to keep it stirred/turned over regularly so the anaerobic bad guys have nowhere to get a foothold

Not sure if that helps at all but hey, I'm a fish geek

msmj

Damn, you can learn anything here. I have a 55 gal with undetectable filters as well as my side hung. Do I need to stir that too.

[Cody Cotyledon]

Damn, you can learn anything here. I have a 55 gal with undetectable filters as well as my side hung. Do I need to stir that too.

Damon auto correct (under gravel) filters..not undetectable...

[the lone deranger]

@Stonk boi first post