i HAVE a problem cant figure it out

[elito]

i have a ebb and flow table,first time hydro,thats in perlite and just covered with a layer of clay pellets to hold the pots from floating,ph 5.7-6.2,nutrients 0.2-0.3 EC ,thats 100-130ppms on a bluelab meter,iv been growing for 2 years in soil but never had problems like these, it starts on the lower leaves so i thought its a deficiency but i dont know what, it looks like rust,they are 7 days in veg. clones from a white russian plant,iv been adjusting the ph from 6.3 to 5.2-5.4 for 3 days in a row is that maybe too much oscilating for them,the water seems to be very easy to ph up or down meaning its not buffering almost at all couse im using a ro filter so i was thinking maybe i shoild mix half tap water half ro

 

[VerdantGreen]

looks like phosphorous def. to me. clones and seedlings need some. also generally look hungry

dont do hydro myself but i would maybe try a little bloom fert if your veg fert is low in P

perhaps a hydro expert can expand on that?? (or shoot it down in flames)

V,

 

[hazy]

Your pH was fine at 5.7-6.2.
Why'd you lower it? Anything below 5.5 is bad. You'll get
So anyway, if your pH is good then you must just need to feed a little more. 0.3 100-300 ppms seems mighty low?


It being on the lower leaves is because it a mobile nutrient like mag (the spots?) and N (they're yellowing).

 

[ItsGrowTime]

100ppm is your problem. You should be at least 600ppm. You're starving them. Feed them!

Once you add some nutes the ph will come down on its own. You're basically just feeding them ph down. That's why they're not happy.

 

[EvilTwin]

elito,
To answer your question about water and ph. I just use straight RO with no difficulties. If you want to add some tap for micro-nutrients...I don't see any problem there. Most buffering is done by the nute manufacturer with the N ratios so don't expect dramatic improvement in ph stability with the addition of tap water.

In my opinion, the ph shifts are not only NOT a problem...I feel it's a benefit by exposing the root zone to a wider nutrient absorption range.

Up your nutes and see what happens.
ET

 

[VerdantGreen]

EvilTwin - as you can see from the pH/nutrient chart there is little benefit letting your pH go below what hazy says above. essential nutes start getting locked out. look at the Phosphorous bar - it is starting to get locked out below 6 and that is one of the reasons why the pics show the brown patches on the leaves - P def.
but obviously the low ppm wont help either

V.

 

[EvilTwin]

Verdant Green,
I could very easily have used the graph to argue my point. I'll take another stab at explaining to see if I can get it right this time...

All nutrients don't absorb at the same ph range...as Verdants graph clearly shows. There are optimal levels for each nutrient and those levels aren't the same. So by allowing your ph to swing through a reasonably wide range, the plant has an opportunity to absorb each element well. Sure, at ph 5.2 it's too low for much phosphorus to absorb...but it's perfect for some of the other nutrients. And then as the ph rises upward toward the 6.2 range the plant can absorb all the phosphorus it needs. So over the course of the two days or so for the swing...all nutients have the opportunity to absorb optimally.

I've been growing that way for three years now (did dirt before that) and have have had one picture perfect grow after another. I shoot for 5.4 to 6.2 but if it goes lower...no worries.

This is not my own theory. Learned that from expert growers on PG before it went down.

One other advantage is that it allows a more relaxed approach to ph adjustment. People who try to keep their res under tight control are always struggling and frustated (or so it seems). I've seen people check and adjust ph twice daily. Just not necessary. I'm away from home and have been for 3 weeks now. A buddy is topping up my res but he doesn't know how to check ph or ppm so no checking. Spoke to him on the phone and plants are doing great. Tight ph management is usually more of a problem then a benefit.

All I really wanted to do is to reassure elito that the oscillations he was referring to were not going to hurt anything. Once he gets his nutes up to where they should be...his ph issues will work themselves out.

Peace,
ET

 

[VerdantGreen]

hi again EvilTwin. i dont do hydro so i wont argue with you i realise that pH is kept a little lower in hydro than in soil. glad you get good results.
i do a similar pH sweep thing in organics by using dolomite lime in the soil and then watering at pH 6. then the sweep between 6 and 7 gives good absorbtion for all the nutrients. whilst some nutrients are available below 5.5, many arent. - and they are all available at near optimum levels between between 6ish and 7.

V.

 

[elito]

Verdant Green,
I could very easily have used the graph to argue my point. I'll take another stab at explaining to see if I can get it right this time...

All nutrients don't absorb at the same ph range...as Verdants graph clearly shows. There are optimal levels for each nutrient and those levels aren't the same. So by allowing your ph to swing through a reasonably wide range, the plant has an opportunity to absorb each element well. Sure, at ph 5.2 it's too low for much phosphorus to absorb...but it's perfect for some of the other nutrients. And then as the ph rises upward toward the 6.2 range the plant can absorb all the phosphorus it needs. So over the course of the two days or so for the swing...all nutients have the opportunity to absorb optimally.

I've been growing that way for three years now (did dirt before that) and have have had one picture perfect grow after another. I shoot for 5.4 to 6.2 but if it goes lower...no worries.

This is not my own theory. Learned that from expert growers on PG before it went down.

One other advantage is that it allows a more relaxed approach to ph adjustment. People who try to keep their res under tight control are always struggling and frustated (or so it seems). I've seen people check and adjust ph twice daily. Just not necessary. I'm away from home and have been for 3 weeks now. A buddy is topping up my res but he doesn't know how to check ph or ppm so no checking. Spoke to him on the phone and plants are doing great. Tight ph management is usually more of a problem then a benefit.

All I really wanted to do is to reassure elito that the oscillations he was referring to were not going to hurt anything. Once he gets his nutes up to where they should be...his ph issues will work themselves out.

Peace,
ET

thanks for all the replys,glad to see so many people wana help

tomorow il up the nutes a bit,can somebody tell me whats the upper and lower level for the ph before i need to adjust it,lets say it gets to 6.5 or 5.2 are those the limits,should i adjust it soon as it gets below or above that,is adjusting ph every day too much or not

 

[EvilTwin]

elito,
Res management is one of those things that is very individualized. You'll find that people do it many different ways. So much depends on how often you change out the res and if you add back nutrients, All I can tell you is how I do it...

First I bring my res back to the desired ppm of nutrients. I like to give it a few hours to stabilize before correcting the ph. As nutrients get used up, the ph generally rises...so the correction is usually down. I never need ph up and don't own any.

I check the res daily just to make sure nothing unexpected has happened but I only correct ppm and ph every couple of days. I drop it down to 5.4 or a tad lower. 5.2 is perfectly fine also. Then watch it as it gradually rises. I wouldn't wait till 6.5ph. That's too high. 6.2 is a better number. So correct at 6.2 or above and drop it down to at least 5.4ph.

That's what I do and it works great.
ET

 

[Lazyman]

More food yes, if you're using RO water it would appear you have a mag deficiency as well, add 1/4 tsp/gallon epsom salts with each watering.

 

[MickTheBrag]

looks like lack of fresh air. have you got a fan blowing on them too.


could be a dose of heatstress.


peace. mick.

 

[elito]

elito,
Res management is one of those things that is very individualized. You'll find that people do it many different ways. So much depends on how often you change out the res and if you add back nutrients, All I can tell you is how I do it...

First I bring my res back to the desired ppm of nutrients. I like to give it a few hours to stabilize before correcting the ph. As nutrients get used up, the ph generally rises...so the correction is usually down. I never need ph up and don't own any.

I check the res daily just to make sure nothing unexpected has happened but I only correct ppm and ph every couple of days. I drop it down to 5.4 or a tad lower. 5.2 is perfectly fine also. Then watch it as it gradually rises. I wouldn't wait till 6.5ph. That's too high. 6.2 is a better number. So correct at 6.2 or above and drop it down to at least 5.4ph.

That's what I do and it works great.
ET

thast what im gonna try from now on

 

[elito]

More food yes, if you're using RO water it would appear you have a mag deficiency as well, add 1/4 tsp/gallon epsom salts with each watering.

im mixed the ro water with tap so i guess that should settle the mg. and cal.

 

[ItsGrowTime]

You sound scared to feed them. It's a common fear at first. Don't worry they can handle it. Get the nutes cranking and watch them take off.

 

[elito]

You sound scared to feed them. It's a common fear at first. Don't worry they can handle it. Get the nutes cranking and watch them take off.

im a little eparanoid,burned some plants before so i like to take it from the lower level

 

[EvilTwin]

elito,
I failed to mention that as I'm checking the res, the very first thing is to top it off with water. Then check ppms and add nutes. Be sure you do it after a flood so you have plenty of time to work. You don't want a flood cycle to start while in the middle af adjusting things. I know that's obvious but worth mentioning anyway. You could accidentally burn the plants if the nutes weren't mixed up good.
Peace,
ET