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Preparing your LECA/Expanded clay pellets/Hydroton before using it as a growing media

Skullman420

Well-Known Member
I will start this thread with stating I have not yet found a really good way of dealing with hundreds of liters of LECA/expanded clay pellets/Hydroton (mostly same shit - different wrapping, some differences I will explain later but only minor - From here on I will refer to this media as LECA.

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The main difference between the different LECA products you can buy under misc brand names is that some of them have been pre-washed, are pH buffered and so on. I bought a shitload from a gardening center. They were Incredibly dirty and the runoff was measured to 11! - I put 5.5 in and get 11 out. So that's absolutely an issue.

Then you have more fancy brand named I tried that is pre-cleaned and "pH buffered"... Well- The ones I bought was buffered to 7.5 - Hardly ideal for hydroponics. So no matter it seems we need to make adjustments - And also the cleaned stuff was full of red dust so it will still need additional cleaning.

You may ask - Why do I need to pH adjust my LECA? - Because if you don't, you will have to adjust the pH of your reservoir 2 times a day for the whole duration of the grow. It will keep raising and raising and raising until it starts driving you crazy. Then you realize it will be so much less work if you just do it proper to begin with - And that is where I am now - Trying to figure out where I am now.

So how do we wash and pH adjust a shitload of LECA?


So far I poured 16x12 liter pots of used leca into a 200 liter flexi tank. I filled it up with water pH'ed to 4.0 with a good dose of Cannazym to dissolve dead root material. I allowed it to soak for 24 hours. I then measured the pH of the runoff. 7.5. That's an improvement allright. I bet we were closer to 10 even after 10 weeks of constant growing. It's Incredible how difficult to do this after the growing start, so get the LECA to the right pH first.

I will now empty the tank and fill it up again with a new batch of clean water pH'ed to 4.0, Then I will measure the pH of the runoff tomorrow. Hopefully it will be closer to where we want it to be. As long as I get it around 6.0 or slightly lower I will be happy. That will make the growing experience so much better next round.

It will take me at least 4 days to prepare LECA for 32 pots my way, but so far it's the only way I have. I am very open for suggestions on how to do this better - Also - LECA floats so I have to keep pushing it below water to get it cleaned off and it is a whole lot of work.

Will update this thread with results as I get them
 

Skullman420

Well-Known Member
Re: Preparing your LECA/Expanded clay pellets/Hydroton before using it as a growing m

UPDATE.

Measured runoff after 24 hours of soaking in pH 4 water. Went from 7.5 to 5.9

That's close enough for me. I will now prepare some buckets of water pH'ed to 5.5 with Canna Rhizotonic. Will give the leca a quick wash with this water before adding it to the pots. Then I will repeat this procedure again with the 16 next pots. A total of 384 liters of LECA. Thinking a few good old bathtubs would be better than this 225 liter flexitank.
 

Skullman420

Well-Known Member
Re: Preparing your LECA/Expanded clay pellets/Hydroton before using it as a growing m

No prob. Found very little info about leca and pH so figured I had to figure something out myself. Strange thing that even the leca they sell in hydro-shops ain't buffered to a good pH for hydroponic growing. Even more strange I don't see thousands of complaints from people using leca and drippers. Perhaps only I have been very unlucky with the leca I bought? I do not know - This method seems to work though. Will update further when I have added the pots to the tables and connected the pumps. Will be interesting to see how stabile the reservoir pH will be now.
 

dj1714

Well-Known Member
Re: Preparing your LECA/Expanded clay pellets/Hydroton before using it as a growing m

Perhaps only I have been very unlucky with the leca I bought?

No You're not by yourself. Seems like every time I use a new bag it's like chasing a ph ghost.
I'm going to try your method and see how it goes.
 

Skullman420

Well-Known Member
Re: Preparing your LECA/Expanded clay pellets/Hydroton before using it as a growing m

I read somewhere you should not allow it to dry out again after the adjustment. So I will ready the table and the reservoir, then fill the pots and then keep pH'ed water running 24/7 for a day or two just to see if it actually remains stabile. I am still waiting for my clones to root, so I have time to experiment a little bit
 
Re: Preparing your LECA/Expanded clay pellets/Hydroton before using it as a growing m

This shit never seems to run clean no matter how much you wash it lol. The missus heard me say " Fucks sake " about 1,843,245 times trying to get mine " clean " over a few days. I gave up in the end, primed it with nuted / ph'd water for another 24 hours and ran with it. :high-five:
 

Guy Cavallero

Well-Known Member
Re: Preparing your LECA/Expanded clay pellets/Hydroton before using it as a growing m

Im new to hydro. 1 bucket so far. I did not know the PH could spike that high initially......WOW, why would it come so high, why would a PH of 11 even be necessary, what could it's other use be?

I'm starting off with a pail or two but my comparison grow between my two white cookies (soil vs hydro), has proven very encouraging (she's twice the size of my soil girl).

Thanks for providing this info DeVille, I'm gonna wash some clay this afternoon then to get some ready for the bean drop on Monday.

Any tips on how yo root an auto in hydro? My plan was to get my taproot started in paper towel, then gingerly into a cloner disc for a week or so to get some growth, then into the Hydroton. I'm hoping for good results but I know the Ruderalis gene is gonna hate the movement til I get her established......any thoughts?
 

Skullman420

Well-Known Member
Re: Preparing your LECA/Expanded clay pellets/Hydroton before using it as a growing m

Washed and filled the reservoir. pH is 6.0 now. Let's see what it is tomorrow
 

Skullman420

Well-Known Member
Re: Preparing your LECA/Expanded clay pellets/Hydroton before using it as a growing m

Im new to hydro. 1 bucket so far. I did not know the PH could spike that high initially......WOW, why would it come so high, why would a PH of 11 even be necessary, what could it's other use be?

I'm starting off with a pail or two but my comparison grow between my two white cookies (soil vs hydro), has proven very encouraging (she's twice the size of my soil girl).

Thanks for providing this info DeVille, I'm gonna wash some clay this afternoon then to get some ready for the bean drop on Monday.

Any tips on how yo root an auto in hydro? My plan was to get my taproot started in paper towel, then gingerly into a cloner disc for a week or so to get some growth, then into the Hydroton. I'm hoping for good results but I know the Ruderalis gene is gonna hate the movement til I get her established......any thoughts?
I would plant the seed directly into it's final media. Especially since it's an auto. They don't like being repotted. I use peat pellets for the seeds, then put them in the leca. Set the dripper to 15 min 4 times per day.
 

Guy Cavallero

Well-Known Member
Re: Preparing your LECA/Expanded clay pellets/Hydroton before using it as a growing m

I would plant the seed directly into it's final media. Especially since it's an auto. They don't like being repotted. I use peat pellets for the seeds, then put them in the leca. Set the dripper to 15 min 4 times per day.
Been meaning to get a manifold. Tomorrow for sure. I was going to try to start my seed in my cloner after the paper towel, but I too know the woes of autos and their pickiness. Seeing as I would love to see this one to the end, you're suggesting that I go with my standard choice of a rapid rooter?
 

Skullman420

Well-Known Member
Re: Preparing your LECA/Expanded clay pellets/Hydroton before using it as a growing m

Sure thing. That works

Been meaning to get a manifold. Tomorrow for sure. I was going to try to start my seed in my cloner after the paper towel, but I too know the woes of autos and their pickiness. Seeing as I would love to see this one to the end, you're suggesting that I go with my standard choice of a rapid rooter?
 

Nonpoint

Member
Re: Preparing your LECA/Expanded clay pellets/Hydroton before using it as a growing m

Get you some Porch screen and make yourself a large sieve. Do 1/4 batch at a time. I have the luxury of being able to work it in my yard but a bath tub or sink sized one would work.
This shit never seems to run clean no matter how much you wash it lol. The missus heard me say " Fucks sake " about 1,843,245 times trying to get mine " clean " over a few days. I gave up in the end, primed it with nuted / ph'd water for another 24 hours and ran with it. :high-five:
 

Skullman420

Well-Known Member
Re: Preparing your LECA/Expanded clay pellets/Hydroton before using it as a growing m

So it raised from 5.5 to 6.5

Therefore I pH'ed the reservoir to 4.2. 24 hours later it had stabilised at 5.8

In a couple of hours I'll check again. At least it doesn't raise to 11 anymore but damn this is hard work
 

Skullman420

Well-Known Member
Re: Preparing your LECA/Expanded clay pellets/Hydroton before using it as a growing m

There must be a simple answer to this. People been growing in leca for decades. They all must have had this problem at some point.
 

Guy Cavallero

Well-Known Member
Re: Preparing your LECA/Expanded clay pellets/Hydroton before using it as a growing m

Any idea why it's spikes on at 11 pH? Is it the clay reaction with water?
 

Skullman420

Well-Known Member
Re: Preparing your LECA/Expanded clay pellets/Hydroton before using it as a growing m

That was the dirty leca from the gardening center. The Leca I bought from the hydroshop spike at 7.5

I honestly have no idea. I really thought cleaning them well would do the trick

Though - It seems to spike lower now than before. I will let it run for a while and see how high it goes before it stops raising. I began with 11. Will be interesting to see. I did the same with a small amount I am usiing in a small tent. That one is spiking at 7.5 like the hydro-shop leca, so it does work, only not as well as I want it too.
 

Guy Cavallero

Well-Known Member
Re: Preparing your LECA/Expanded clay pellets/Hydroton before using it as a growing m

Funny to come across this just as I'm about to throw my next seed into Hydro..... Watching in Earnest. I'm going to pH my clay Pebbles tonight when I get home and let you know what mine came out at. They are just from the hydro store.
 

Nonpoint

Member
Re: Preparing your LECA/Expanded clay pellets/Hydroton before using it as a growing m

I thought I read once upon a time that it used to not be a problem. The factories/quarries that pumped out quality LECA have closed down and we are left with junk.
There must be a simple answer to this. People been growing in leca for decades. They all must have had this problem at some point.
 

Skullman420

Well-Known Member
Re: Preparing your LECA/Expanded clay pellets/Hydroton before using it as a growing m

I don't know what I am doing "wrong" really. Can't remember this was an issue first time I grew in leca 4-5 years ago. But I didn't check pH much back then. Just had those color strips. Not very accurate
 
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