How does perlite effect PH?

I probably have a very simple question. Here's some background info.
My Amish friend has some babies in 16oz keg cups, they look great, and are still in the "seedling" stage of life. All is well, however, when watering with RO water, adjusted to 6.8, (and even down to 6.7) the ph of the runoff still comes out at roughly 7.2-7.28? The soil is foxfarm lightwarrior, and the very bottom inch or two is solid perlite. (Hoping to aide drainage although the fflw is very light and seems pretty excellent).
After 3 waterings, nothing added to the RO except the ph down, the runoff is consistently coming out at the prior mentioned levels. Why? Does perlite have that kind of impact on ph? Is it the soil itself?
Considering that the runoff is 7.2ish, that's about a .5 point spread, which I guess means the soil ph is roughly at 7.0ish?
So should the RO water be adjusted down to 6.5ish to reach the desired soil ph, is this over thinking at this stage of the game? Or should they continue to be watered with ph adjusted RO to 6.7 6.8ish. My guess was that the perlite in the bottom was directly causing the runoff to come out higher than it actually is in the soil itself, in which case I am thinking that I should keep that in the back of the brain. Does this make any sense, a little advice, experience would be greatly appreciated. In the mean time I will continue to search the boards.:jointsmile:

well I am not sure ?? someone with more exp will know tho , but in the meantime you could put some perlite in a cup and run some water thru it and check the ph and see. I'm betting its micro nutes in the soil .. goodluck

Roger that! THanks veggi, don't know why I didn't think of that. I will post my experiment with the perlite ph testing. I will just run some water through some perlite and test the runoff, then through just the soil. I will post what the results are and then maybe you or some others could help determine if the soil ph is looking good. So far the babies seem to like it and they don't appear to be showing any signs of stress, so maybe this is all worry over nuthin' much. Again in the mean time if anyone else reads this and has any wisdom to add then by all means put your 2 cents in!

As far as I know...perlite is ph neutral....whatever your water ph is...it should stay the same going in...IMO....:twocents:

Ah..
Well I know you know your stuff DutchPimp, and that makes sense. I am pretty sure I have read that before too. PH runoff that high in soil just caught me a little off guard, my Amish buddies limited experience has only been with soil that had significantly dropped ph. I bet you and veggi have already answered my question then. Just for shits and giggles I am going to test runoff with just perlite thought to see tomorrow, I will post my unspectacular findings.
Assuming it is the soil, then the soil ph is sitting at about 7 even? (Water in @ 6.75, runoff out @ 7.25?) Is that right? If true then the water needs to be going in @ 6.5 then, assuming the runoff comes out at that point @ 7.0, then my soil would be at 6.8ish? Is that reasonable, and ok with very young plants? Thanks again for the input.:)

Hey 8KS, interesting. Your question seems to be answered. I think I read a bit about it with Stinky's 'Donkey Dick' gro. Mite drop in there and see! :) Not sure. Just a thot. Or a senior moment!

Sorry no pers. mess. anymore! Since this is your thread, hope U don't mind! How is the family fishing going? Guess, we could drop a thread in parenting for that? I am interested in it! :thumbsup:

And of course, I am learning all I possibly can. So, this info helps me out! pr:hippy:

Hey thanks for the post sir and the tip on Stinky's DD grow, I will check that out.
Just had a near catastrophic emergency, I mean my "Amish" friend did anyway. About an hour ago his main intake fan just failed horribly! Luckily I was near by and was able to tinker with it and got it back up and running, temps hit 90, but only for an hour or so. Phewww!
That's a great idea to start a fishing thread, or children's activities thread in the parenting forum. I will get that going unless you beat me to it.:D Haven't been out all week so maybe tomorrow evening we will get out there again.
Thanks again sir.
Holy shit, just saw on fox and friends right now, some little 3 or 4 year girl in NC is on, she just caught a 20 something lb flathead on a 4 foot long barbie fishing pole! How funny is that literally as I was typing this post!

If you have a .5 rise in pH coming out of the soil, then your soil is probably even higher than that, I would guess at 7.5, maybe even a little higher.Once you run your test thru the soil only you will know.

McDanger is correct! Your runoff pH is a number BETWEEN the true soil pH and the water pH. It is a measure of how your liquid and your medium interact.

Um ug.
So should I be watering with an even lower ph to get my soil to 6.8? Or maybe I should just start flushing everything now to get that number down. Is all of this a potential promblem, or will the soil eventually come down on it's own. I have always had the opposite promblem prior to this, (soil to low) so this is a new one on me. My other concern is that these plants are just babies, just starting their 3rd true sets of leaves. They will be transplanted as soon as I can see some roots coming out of the bottoms/sides of the cups. Would they be ok until then, they will be going to ffof from where they are now.(fflw)
All in all, from what little I can see, the plants seem to be just fine, but I know that could all change very quickly and want to be as proactive as possible. So what would you do?
-Continue watering with ph'd RO @ 6.8?
-Flush to get the runoff reading @ around 6.5ish? (Guessing that would put the soil @ around the right mark.)
-Or just continue to water with the ph'd RO @ around 6.5ish and monitor the runoff in hopes that it'll come down?
Am I over-concerned about something that really isn't a big deal or would you say this needs to be addressed and fixed now. I am sure the right answer is to flush since that would be the biggest pain in the ass for me at the moment.(I have to get my RO from a local store machine.ug.) I was slightly concerned to flushing such young seedlings. Hopefully I will be able to get some time in there today to do some experimenting. Thanks for the input again.
I love this site.:thumbsup:

I am no expert, but your plants look good. If you want to lower it a little, to say 6.5 or 6.4 I think that would be OK. I am not sure you need to though.Sorry, no pics. I read a lot of posts today.

Update,
After significant reading, I found some info.
On another forum I found someone with the exact same issue. Although fflw is supposed to be ph balanced to 7.0, it appears that it is not uncommon for it to come in a little higher.
I have decided to not flush, but over water, (do a half assed flush) for the next few waterings with ro h2o ph @ 6.0- 6.2, I tried this today and was able to get my runoff readings down to 7.0 from 7.2. From what I gather the fflw, will in time come down, and that it has, um shit I don't remember now, but it is something that helps buffer or keep the soil around 7. Eventually I am guessing this will run out with a few more pseudo flushs. Again, the plants don't appear to be suffering from anything that I can see, and since they are so young, from what I understand they are getting all their nutritional needs from themselves at the moment so I am not really sure if any of this is an issue to worry about. Just the same though, I will work on getting my runoff readings down to around 6.5ish. That would put my soil around where it needs to be I think, please correct me if I am wrong!
Also is there any harm in watering with 6.0 for seedlings considering where the ph of the soil is currently? I hope not!
On a side note, has anyone had any experience with ro h2o ph raising a half point to a point? I was under the impression that ro h2o should be more stable once it is ph'd. Any thoughts?

you are on the right track. I would not go any lower than 6.0 for your 'flush' water, and now you'll just want to maintain a watering schedule at 6.7 or so, which should keep you right where you need to be until the lime in your bagged dirt is used up. That's the most common reason to see what you had been seeing in the past, which is a DROP in pH over time- the lime raises soil pH and keeps it close to neutral. When it is gone, the component acting most on the pH is the peat itself, which is acidic. There's another explanation in the 'continuous canopy' sticky which has an FAQ link embedded in it somewhere.
You will be fine. Now on top of all this, remember that if you are flushing a lot, you need great drainage and air flow around your plants so they don't end up waterlogged.

Thank you so much Miss Mam!
Hopefully the soil ph issue will be resolved after a couple more HAF (half assed flushes) with the 6.0, if it goes down .2 every time! This has inspired me to go ahead and get the ffof mixed with the rest of the fflw I have, add some lime, and get it tested and ready for it's eventual use. I really misunderstood soil runoff, so ideally you really want your runoff coming out @ about 6.5ish or so, that's good to know. That kinda explains some stuff that happened last time! Poor plants. Oh well they are all dead and gone now!
Aww Drainage, yes. You would be proud! Not only of the drainage for the cups that they are currently in, but of the table that they are on! I got these handy dandy plastic storage shelf things that you just put together to, store shit on, well anyway, I took 3 of them and put the legs on so they are all side by side. They have like maybe half inch slots all through the shelf thing, so instead of having my cups, and in the future pots sitting in those damn dishes, they are just sitting on top of the "make shift table that is supposed to be a 5 level shelf. I got some panda plastic and made a sweet tray that the legs are in so that when my cups/pots drain, the runoff just falls straight down and collects about 2 ft away from the bottoms of the pot/cups so they aren't sitting in any water at all! Of course extra extra holes in everything in the bottoms and up the sides! And it is so easy to just sop up the runoff and wipe it clean. I may get to play around with a scrog in the future too, the legs are hollow, and I can easily just drop in some poles that will allow me to tie a screen on. It's pretty sweet really, might not sound that cool but it is to me. I made it with my hands and it works!
Now if I could get a handle on my damn temps! That's one good thing I guess, I'm running right at 85* so in those small cups with all the excellent drainage I have, they dry out in like 2 maybe 3 days tops! Where as before.......ug. Anyway thanks again to you and everyone really, so much good info here this place is a friggin' gold mine!:thumbsup:
Eventually I will hopefully be able to post a grow log, once this is all said and done anyways. I am keeping a good journal now, and collecting all the pics, so after it's all said and done I will put it together in 1 nice shot as a tribute to you and all the other wise growers here. Hopefully it turns out well!
But really, the table is sweet!:D

hey kush I found this website on perlite P.H 7 neutral
www.perlite.net

Thank you. I believe everyone that it's neutral.
I am still having mixed issues, a few are still coming out around 7.0, a most are still anywhere between 7.2 - 7.5ish, I am getting pissed. I think Now also getting some what appears to be burning? WTF, it's fflw, I don't know how that's happening, I am not adding any nutes, just extremely low ph'd ro, around 6.0- 6.3ish, so I don't know if the low ph'd water could cause this, or if it is in fact due to nutes in the soil. They all still look fairly healthy, but I am just going to throw up my hands on this one, don't really want to flush again, (3rd time), hopefully the lime will work itself out. If not, they will be re-potted sometime within the next month, so maybe that will help things a little. Thanks again for the help folks.

yes its gotta be soil!! its too hot!! I've been using fish emulsion and the ph after mixing is orange!! low!! needs yellow, but everything looks ok no burning, gonna get some ph up or use baking soda I hear works as ph up.
check in my picture album got some info in there, work in progress

Yeah that fish glop is mad acidic. Be real careful with Sodium bicarb- you don't want sodium around your grow. Adding LIME to the soil mix instead does the same thing, without the sodium. It's Calcium carbonate instead of Sodium bicarbonate, and plants LOVE their calcium! It should be considered a 'macro' nute for how important it is, IMVHO... lol!

Quote:

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Adding LIME to the soil mix instead does the same thing, without the sodium. It's Calcium carbonate instead of Sodium bicarbonate, and plants LOVE their calcium!

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Do you just dice up a bunch of limes when you transplant and mix them in?

Haha! Cute!
That would be ACIDIFYING the soil lol! Save the limes for your Tall Cool Ones.
Lime in the gardening sense would be pulverized limestone, or Calcium carbonate. It comes pre-mixed in a lot of soils [ most] and can also be purchased bagged if you need to add more.
I just added a link to my siggy that has a long post about all this stuff... gimme a sec... it hasn't updated yet.

skush...I have found FFoF to have problems with Ph, and WATERLOGGING...I would add some perlite to that before transplanting. I have had issues with the last 2 grows from trusting the shop guy that FFoF was light enough on its own...And the FF runs hot as hell too....
just my :twocents: to help ya prevent a possible problem..

whiskeytango

heh....dice up limes...thanks for that, I needed a good laugh this morning

baking soda ,man I used it this morning before loggin on,geeez that stuff is strong! I used just a tiny amount from tip my finger! I'll be purchasing PH up.
I got the bakingsoda tip from the Spray 'n' Grow website. ofcourse not a mention of the Harm it can cause! ty Stinkyattic :D

Quote:

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Originally Posted by SnSstealth

skush...I have found FFoF to have problems with Ph, and WATERLOGGING...I would add some perlite to that before transplanting. I have had issues with the last 2 grows from trusting the shop guy that FFoF was light enough on its own...And the FF runs hot as hell too....
just my :twocents: to help ya prevent a possible problem..

whiskeytango

heh....dice up limes...thanks for that, I needed a good laugh this morning

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Roger Wilco on that. I have a big ass bag of perlite, in your opinion, how much would you add. I was going to start with 2-4 sacks of FFOF, should I dump the whole bag of perlite in with them? Right now I just have the 2 bags, but I am thinking I may need to get more obviously, (just what I could afford at the time), to get me through my first round anyway.
So is FF adding lots of lime to compensate for the "hotness" of the light warrior and ocean forrest or what? I thought that was really wierd that I was seeing burning, while the soil ph was so high too?
I hate to do it, but when I get the ffof mixed and ready, I am going to really flush it out really well until the ph is perfect, but man I can't help but think I am going to be flushing out all the goodies that cost extra! Damn it! Oh well, guess that what my veg nutes are for. Here I was thinking that I was getting ahead of the game by using ff, it's turning out to be more of a pain in the ass than the soil I got from the nursery for my last grow. Good learning exp. I guess!:jointsmile:

hey Kush I used peat pellets for first week for seedlings, by first week I mean first week. I did the paper towel sprout method and then put them in the peat pellets for 1 week then I put them in the FF/OC in a yogurt cup and only used water for week 2 as i was sure the FF/OC had enough nutes in it. I did'nt have much problems with that method will be using it again. I am not too familar with the LW mix that is a seedling starter mix. anyhow I'll be sticking to the process I used it worked pretty good. as for perlite everyone is using a 60%(soil) to 40%(perlite) I will be also I got the perlite today.
did you check out my picture albums they are hard for me too see I was looking for feedback on picture Quality on the Bible album..peace ..:jointsmile:
oh and I was also asking myself that same question how much lime are they putting in FF/OC

Well, hopefully I am not jinxing myself.
Just wanted to post a follow up.
I got a little ancy the other night, I had been waiting for the babies to get to their 5th leaf sets before transplanting them but I said fuck it and went ahead and did it anyway.
By this point, some had started to get their 1st leaf sets turning brown and dying, and growth had slowed to a crawl. I had chalked this up to ph issues, but anyway.
As I re-potted them, I discovered that nearly ALL of them were root bound even at their very young age! I was shocked!
2 days later, there has been a drastic turn around. They all look lovely, and have started to vigorously grow again! They have greened up nicely! Of course the plants with the dead leaves still have them, but now they actually have spurred on new growth! I am happy, now I just wish I had started them in the pots that they are now in. I imagine they will likely need to be re-potted yet maybe by the end of the month, where they will likely finish. I am going to try to finish them in the 3 gallon pots, hopefully they will be big enough, I am trying to avoid the 5 gallon pots, if I can. They are now in the FFOF, what's funny, is that obviously they were still in there original fflw homes when transplanted, but once they went into the ffof, I checked the runoff, and....
H2O in with super-thrive, 6.6
H2O out...da da da daaaa, 6.7ish!
As you can imagine, I am very happy as compared to what it had been, even after multiple half assed flushing attempts with very low ph water.
So thanks for all of the advice folks!!!! I will be posting a grow log hopefully soon, this is a run of 10 MK and 10 AI, 1 GC, (crossing my fingers hoping for a female to clone and mum!) and 3 lowlife low rider mystery indicas, (they were free, so what the hell huh?) Once I get the room cleaned up and looking presentable, I will get some pics, post some detailed info and start the log. Hopefully you all will drop in and keep me from doing anything too catastrophic!:thumbsup:

P.S., I have started to consider switching them off the RO H2O, and using tap, I haven't decided yet though. If I don't and stay with the RO, considering the soil they are in FFOF, would you, and when would you start to supplement cal mag? My thoughts were for basic veg purposes, that they would likely be ok with what is already in the soil for 2-4 weeks, but I am wondering about micros?
So which would you do? Or would you just go with tap water, and forget about the cal mag. My tap is about 380ish ppm, about 8.5ish ph? (Yeah I know, not good, this is why I started using the RO).
I also have some Liquid Karma on hand, and have wondered what good or harm would be to add some very very light mix to my water as well? Any thoughts? Should I just leave well enough alone for now?
Thanks again!

Hey all, hopefully you have subscribed to this if you posted here previously. As promised, I have started a grow log. The link is in my siggie, AI and MK Perpetual Grow, (Hopefully)! Stop on by!:D
Lots of pics! Check out some of the damage that was done early on and where they are at now!