Flushing big containers

[Canachris]

I'm growing in 15 gal containers, everything I've read on flushing say to flush with 3 times the size of the container. 45 gallons is an insane amount , with 2 containers that's 100 gallons. is my measly 4 gallon flush a waste of time ?

 

[013]

Hey Canachris, mind if I ask - what are you hoping to accomplish with the flush? Some nute companies recommend a flush at certain intervals and they have spent coin for the R&D so that’s fine. Yes flushing can clear chemical salts from the grow media, however it doesn’t flush nutes from your buds or improve taste of the finished product

The 4 gallons is not enough to be considered a flush tho, the reason it’s 3X the container size is to try to overcome the density of the soil fully saturate the media with same volume as container size causing significant runoff and then repeating the process 2 more times. It’s forced rinsing or waterboarding a plant.....

personally I try to avoid a flush but I save it for an emergency situation, of course I’m not using bottled nutes. Whatever you decide is fine and please consider all other opinions.

Thats a beautiful specimen you have grown!!!

 

[Canachris]

the nutes I'm using call for a flush to prevent a buildup of salts. guess I need rethink growing in such big containers. Thanks for the input

 

[Canachris]

this may be a stoned thought,but... if the container full of soil is saturate to runoff after 2 gallons shouldn't 3 times the volume be 6 gallons. if I were to block of the drainage holes the container can only hold 2 gallons before overflowing. I need to light up again .. lol

 

[bluter]

yeah ... i wouldn't run 45 gal through lol

i'd probably go with the 6 gal total as well. three 2 gal waterings in a row. you could also pop a little h202 in and watch them surge for a day or two.

edit : water three times to 10% run off or so.

 

[bobrown14]

the nutes I'm using call for a flush to prevent a buildup of salts. guess I need rethink growing in such big containers. Thanks for the input

Thats bs - you dont need to flush.

The reason is CEC = cation exchange capacity of soil.

45 gal of soil if you have a proper mix you wont need fertilizer.

Why go to the trouble to mix up that much soil and then add fertilizer to it??

Just grow in a proper soil mix and leave those bottles behind.

Coots Mix is a good one. In 45gal you will have plants that are HUGE. Be best for outdoor.

Back to your salt build up. What salts are buiding up in soil??

I think you are confusing SOIL-LESS (coco/peat/buckets etc) with SOIL. They flush soil-less medium, we dont flush soil because of CEC. Its chemistry and physics at play for the reason flushing doesn't do what you think it does in soil.

And yes all that water running thru the soil is going to ruin your grow.

 

[Canachris]

15 gallon containers... not 45 gallon containers,

 

[Emilya Green]

I will weigh in too. If you are running a nutrient line, like Fox Farms, that strongly suggests that you do a proper flush at certain intervals to get rid of accumulations of salt, it would be unwise to listen to anyone who claims you should not follow the directions. The manufacturer best knows their product, and I see the best grows are ones who strictly follow the guidelines provided by those who really know what's up, the scientists who made the product.

A proper flush is 3x the container size, but... you can use wetting agents like sledgehammer, that allow for a quicker dissolving of the salt trapped in the soil, and allow it to get out of there easier. I have found that warm water works better than cold water to move the salt out faster and not require as much water.

You are right about the need to rethink large containers... they are a huge commitment. When you are dealing with that much soil, it makes much more sense to use organic methods and/or nutrients, that do not leave salt behind so they don't need flushing, instead of synthetic nutes.

Next to last point, salt lockout is a thing. Soil can only hold a certain amount of nutrient, its cation exchange capacity. Salt unfortunately likes to drop into those slots instead of nutrient, and over time the soil can no longer exchange nutrient to the plants, and this is called a salt lockout. Luckily, salt dissolves in water, so a flush can remove it while not removing nutrients that are locked in the soil, and everything can get back to normal.

If you are running synthetic nutes, salt does build up. The most critical time to clear the soil of this salt is at the 6 week point, just as the buds are going into their final stretch. Flush right here and you clear the pipes for the plant to be able to uptake everything it needs for a fantastic finish. Flushing for any other reason than to clear salts, such as to somehow cleanse the plant for sweeter taste at the very end, is mostly not worth the effort.

 

[Canachris]

thanks for the info. I had planned to go all organic this grow with the roots organic terp teas... but my grow store didn't have all the different teas in stock when I had the $. but next grow I will be better prepared

 

[bobrown14]

15 gallon containers... not 45 gallon containers,

My sentiments still apply - sorry thought you wrote 45 gal which sounds pretty large for indoor. I'm running 45's outside right now .... prolly was thinking about my own there.

Yeah so whatever size pot you have - flushing soil doesn't work because the soil has whats called CEC or Cation Exchange Capacity.

This is the soils ability to hold onto nutrients.

They are chemically bound to the soil particles and are only released by the chemical reactions that take place in the Rhizospere of the roots of plants.

There's an interaction between the plants roots and the soil bacteria. This interaction releases those nutrients that are chemically bound to the soil particles.

This is the science and I could go a lot more in depth on this.

There's a lot of good science out there and a good read if you're so inclined.

Edit: if you think you need to flush then cut back on your fertilizer.

Also there will be no amount of water you can push thru the soil that will break the chemical bond between the nutrients and the soil organic matter. ZERO.

 

[Canachris]

Thanks for the info. my next grow will be all organic.

 

[bobrown14]

I use Coots recipe... its a good one and very few amendments.

There are others but this is the one I started using back in 2013 - I'm still using that same soil and amend at up pot. The soil mix gets a lot of use too. I run 6-8 rounds per year in flower perpetual and VEG constant non-stop.

 

[Fuzzy Duck]

Mmm this ol chestnut I#m surprised the old myth is still floating around