Let's Talk Hydroton / Grow Stones / Expanded Clay

I'm curious what everyone is using for flood schedules in a 100% hydroton in different systems.

Please note the type of medium, the type of pot and the system your using.

For years I've always used the general flooding schedules, flooding every 3-4 hours and not flooding at lights off, with real hydroton.

Recently I've come across something strange, I'm not sure if it's the strain I'm growing or the new mediums I'm using since most hydro stores do not carry true hydroton anymore.

I've been using PlantIt clay pebbles. Most strains are OK with flooding every 4 hours in a flood and drain tray in which ever pot I'm using, be it smart pots or mesh pots.. But I have a particular strain that will not let me water more than every 8 hours. The roots go brown and die and the plant suffers from overwatering stress and grows really shitty when flooded more often. Weird right?

I'm curious if the new plantit brand pebbles hold more water or something? Obviously when the plants get older they can handle more floods, but I've never had a problem with any plant being flooded every 4 hours, clones or plants, except 1 strain, Larry OG, that I had to flood every 5 hours to get them going well I think..

How is my hydroton overwatering my plant, can different kinds of hydroton hold more water than others?

I am doing a test and watering a new batch of the particular problem strain every 8 hours and the roots are bright white and bigger than the other batch in a 1/3 of the time, and healthy..


So what's your take on flood schedules and what type of pebbles are you using? Any problem strains that need less watering? I've had strains that would die in a day if I didn't flood every 4 hrs, so I want to know if it has to do with the new type of clay pebbles or if it's just this picky strain.

I'm just here to rock out, dude.

ttystikk said:

I'm just here to rock out, dude.

Click to expand...

Me too man, me too

I've read ALOT about the plantit brand pebbles messing up people's pH or something, but I've not noticed that. But I've read it was also messing up their roots in the same way as I'm seeing with one strain. Roots get really shitty, the stems purple and growth slows. I need to get to the bottom of this. The strain I'm growing is one of the easiest strains to grow which leads me to think it's either my medium, or the strain is still sick. That's the only two options, since all my strains use the same reservoirs and it's only one problematic strain. Which makes me think it's that plant, but then changing the flood time wouldn't matter, which that in fact did help this strain, so wtf. I don't know haha

Rinse the rocks well before using them. Rinse when reusing... you do reuse them, right?

I don't use that brand, but I used hydroton- and didn't like how the pebbles were really TOO round; they'd roll all over the fuckin' place with any little spill and they didn't support the plants very well. Now I'm using a similar material that's a bit more irregular and it's much easier to work with.

I haven't encountered any of the problems you're describing, sorry I'm no help there.

I use expanded clay media because it's indefinitely reusable, neutral and easy to work with. I don't run flood n drain past veg, I switch to continuous topfeed over RDWC in the last weeks before they hit the bloomroom, and throughout the glowing cycle. This is where their drainage advantage can be put to best use, I believe.

Whats the plantit brand look like?

Right on ttystikk, it sounds like we use similar clay pebbles, the ones I use are irregular shape too, those are the ones giving me the issue. I do reuse them and make sure no roots are on them and I rinse them in the shower for 15 minutes before planting anything in them. The round ones are a pain to use, but those are the ones that never gave me an issue, but I don't think I've grown this strain in the round ones, just the plantit brand. It's wierd, maybe it really is just the strain, I have no idea. But I'm about to pull 22 plants out of a tray and throw them out because their roots keep dying and getting mushy. It's not root rot because there's no smell or anything, just mushy drowned roots. Maybe the plant I took the clones from had a problem or something, the clones were so damn healthy looking though, then they went to shit within 7 days. It's just driving me crazy trying to figure it out, I think I might just give up growing the plant since it's non stop issues but all my other gear grows perfectly. It's a headache wondering if it's the pebbles or the plant

These are the plantit brand fandango

I was watching my 4x4 table today,the table was level and I found water sitting in the channels,so I tilted the table to drain.
I wonder if the plant you have is sitting in water 24/7?

There is a little bit of water in the channels but not very much, I keep the trays sloped towards the res. I thought the same though, but all the other plants are great in the same trays, even another batch of the problem strain are doing OK, but all 22 of the other batch are just boo boo. The only thing I've done differently with this new batch is flood every 8 hrs instead of every 4, but they also did come from a different mother plant, but I'm not sure if that matters much. This gg4 has given me so many headaches and it really shouldn't because it's a simple strain to grow so I'm like dumbfounded

The F&D table that I'm currently using does six, six minute flood and drains every 24 hours. In this table the pump comes on for three minutes and it takes exactly three minutes to drain. As mentioned, it is very important to wash the hydroton/clay/lava rock pellets well before using them.

AlphaPhase said:

There is a little bit of water in the channels but not very much, I keep the trays sloped towards the res. I thought the same though, but all the other plants are great in the same trays, even another batch of the problem strain are doing OK, but all 22 of the other batch are just boo boo. The only thing I've done differently with this new batch is flood every 8 hrs instead of every 4, but they also did come from a different mother plant, but I'm not sure if that matters much. This gg4 has given me so many headaches and it really shouldn't because it's a simple strain to grow so I'm like dumbfounded

Click to expand...

I have my 1 gallon pots in the bull pen,full of hydroton rock,waiting for some rooted cuts going on in my 32 site ez-cloner.
Currently my tray has 32 x 6" RW cubes...these plants get 4 floods of 15 minutes.
7 days into flower.

Bird Mcbride, that is a Hella fast flood and drain! What size tray is it and what size fittings do you use for the fill and drain? My 2x4 tray takes 6 minutes to fill and about the same to drain but I let them run 1 extra minute after the hit the over flow.

You're using the same flood schedule I've used for years with hydroton fandango. I've never really used rockwool, but I know if the root system is good and you only flood up 1/2 of the rockwool, that timing works good.

AlphaPhase said:

I'm curious what everyone is using for flood schedules in a 100% hydroton in different systems.

Please note the type of medium, the type of pot and the system your using.

For years I've always used the general flooding schedules, flooding every 3-4 hours and not flooding at lights off, with real hydroton.

Recently I've come across something strange, I'm not sure if it's the strain I'm growing or the new mediums I'm using since most hydro stores do not carry true hydroton anymore.

I've been using PlantIt clay pebbles. Most strains are OK with flooding every 4 hours in a flood and drain tray in which ever pot I'm using, be it smart pots or mesh pots.. But I have a particular strain that will not let me water more than every 8 hours. The roots go brown and die and the plant suffers from overwatering stress and grows really shitty when flooded more often. Weird right?

I'm curious if the new plantit brand pebbles hold more water or something? Obviously when the plants get older they can handle more floods, but I've never had a problem with any plant being flooded every 4 hours, clones or plants, except 1 strain, Larry OG, that I had to flood every 5 hours to get them going well I think..

How is my hydroton overwatering my plant, can different kinds of hydroton hold more water than others?

I am doing a test and watering a new batch of the particular problem strain every 8 hours and the roots are bright white and bigger than the other batch in a 1/3 of the time, and healthy..


So what's your take on flood schedules and what type of pebbles are you using? Any problem strains that need less watering? I've had strains that would die in a day if I didn't flood every 4 hrs, so I want to know if it has to do with the new type of clay pebbles or if it's just this picky strain.

Click to expand...

Those plantit pebbles aren't new. I've been using them for 2-3 years. I have an ebb and flow System with 2 gallon buckets and flood 4x per day at 15 min. I never had any ph issues or root issues while using them. I don't clean them any different than I did with hydroton. Just rinse them until the run off is clear.

The only thing I watch out for is setting my 4" rock wool cube to deep in my ebb and flow bucket. Until the roots get going I only water 2x daily.

I am about to set my cuts into a 2" rw cube,from the ez-cloner.Than set the rw into the 1 gallon pot of hydroton...do I need to hand water at first?

growstones. made right here in the USA too. hold most air and water of any media.

I hate plantit brand got 3/4 of 45l bag I refuse to use. To the point I only ran 8 of my 12 ebb flow buckets. Threw 30 clones away that where really taking off. The plantit crushes very easy, smells of sulfur, and never seems to come clean.

Now I am using hydrocorn and love it, rock solid ph, easy to clean and you need a hammer to break them. I'm running 4 different strains, flooding every 3 hours during light, and once at night. The plants seem to like it. Day 10 of flowering, strains ar bubblegum,blue cheese,honey banana, and rainbow jones. Next week i think I'm going to stop the night flooding. HYDROCORN gets my vote!

adower said:

Those plantit pebbles aren't new. I've been using them for 2-3 years. I have an ebb and flow System with 2 gallon buckets and flood 4x per day at 15 min. I never had any ph issues or root issues while using them. I don't clean them any different than I did with hydroton. Just rinse them until the run off is clear.

The only thing I watch out for is setting my 4" rock wool cube to deep in my ebb and flow bucket. Until the roots get going I only water 2x daily.

Click to expand...

2 or 3 years is pretty new to me lol. We use the same system, I have the 2 gallon flood buckets too and flood about the same. In flower I like to flood 4x. I don't use rockwool though so that's why I'm really really curious as to the root zone issue. I'm going to have to chalk it up to just the strain I guess, or maybe a bad batch of plantit pebbles if some people use them with no issues and others have issues with them.. Maybe they did have some quality control issues with plantit brand because I noticed some are discontinued by manufacturer now.

II set the flood schedule on the problematic batch of clonesto flood in flower when lights come on at 8pm and another flood at 4am. I've never flooded only 2 times with hydroton under 1000w hps, if they aren't dead today then there's definitely an issue somewhere between the hydroton I have I'd have to assume.

fandango said:

I am about to set my cuts into a 2" rw cube,from the ez-cloner.Than set the rw into the 1 gallon pot of hydroton...do I need to hand water at first?

Click to expand...

I handwater root plugs at first so I bet it's similar with rw. Definitely handwater until the roots get into the flood zone, then you can flood.

I'm going to get some hydrocorn and some grow stones and see what I like, I've not used either. Toaster strudel is right, these plantit brand crush to dust and do smell a little funky.

I don't know why my hydro shop only sells plantit, wtf. I'll have to order online I guess.

This is the reason why I'm stumped.

These are the clones I planted into the plantit brand pebbles. They were huge and had 18" roots.


I flooded them every 4 hrs. Within a week they were looking like this


Those clones should easily handle a flood every 4 hrs in veg. But they didn't. All of the other plants are fine though, but all 22 of these are not. It's a head scratcher. I'm pretty sure I used a brand new bag of plantit to transplant them as well, I don't think I used old hydroton. So I'm stumped still