My PH keeps dropping

[rr14]

Hi guys. I have a 14 gallon rubbermaid tub. The bottom 5" of it is a res dwc style. The top part has aeroponic sprayers. Water is pumped out of the tub to a shurflo pump, throug a approx 40-60 micron home depot filter, and then sprayed at high pressure into the chamber like a mist. The chamber is completely closed so leakage out is non-existant. There is a bubbler in the res which blows in air from outside the grow area. Res temps were 68 yesterday when I checked.

Nutes are a 900 ppm combo of zone, liqid carma, sensi cal, and the advanced 3 part series. Prior to adding nutes when I do a complete res flush (weekly) I check the ph and ppm. Plants are 2-3 weeks into veg from clone. Plants are about 8" high and are branchy. Roots for the most part are pretty white(I have two that have stained/dried out root (the part out of the res) frm a pump failure. Other than those two everything looks great.

The problem I have is that every day the ph drops. Over the weekend I left with it at 5.80 and when I came back it was like 4.9. This is over 4 days. Last nigt I put it at 5.85 or so and today it was down to 5.6 only about 7 hours later.

What gives?

 

[BigAl]

Your plants are probably taking more water than nutrients. As you would already know, adding nutrients to water lowers the ph.

Is it possible that your misters are contributing to the loss of water through evaporation?

This is where checking the ppm regularly comes into play. If your plants are taking water and leaving nutrients in the reservoir then you are feeding them too much.

 

[MynameStitch]

i WILL HAVE TO AGREE WITH bigal here, 8 in tall plants at 900 ppms?

Wayyyy toooooooo high imo, bring the ppms down to about 400.

Are you using RO water?

 

[rr14]

Correct. I use r/o water. I bring it up to 200 ppm with sensi cal and then add zone and lk. I then add the 3 part advanced nutrients.

I'll go a little lighter this time around with the ppm. I'm due for a flush.

I came home from work and the ph was 6.08 which is really close to what it was when I left for work. This struck me as wierd because it seems stable today after I posted this question versus where it was yesterday and the day before, ect.

 

[MynameStitch]

200 ppm of cal mag alone? dude thats outrageous... normally you only need like 2 ml of calmag per gallon.......

Or is it with the other 2 additives LK and zone?

 

[rr14]

to bring it up from 15-25ppm, I add 25 ml of sensi cal from advanced nutrients. On the jug is says to add 1.25 to 2.5 ml per liter. So I'm actually on the low side of the instructions.

How do you treat your r/o water?

 

[MynameStitch]

You can only get RO water by using a reverse osmosis system, there is no other way to get RO water.

 

[rr14]

I should rephrase that. I meant something to the effect of "when you use r/o water, what do you add to replenish some of the desirable minerals that are strppped away by the r/o process. "

 

[MynameStitch]

Ahh ok! You use things like cal-mag, sensi cal, earthjuice microblast, earthjuice catalyst.
Earthjuice microblast has every micronutrient but one or 2, I know it does NOT have calcium,

so if you pick that one you have to add cal mag with it.
Cal mag is the biggest one peeps use for there setups, it does the job well too.

 

[Guest]

rr= sensi cal is the shit aint it i use it. my god does it have a nice full compliment of micro mutes or what!

stuff like cal mag and magical are kinda like sensical but with only iron, mag, and cal. if you have read about stuff like this youll see that if using cal mag or magical you have to be carefull cause it will caue inbalances of other micros.

this is why sensi cal is and invaluable product because no mater how much you use all the micros are perfectly in proportion with each other and wont lock out.

the goal with treating ro water is to get it around 100 ppms of well balanced micros. 200 ppm is what you get when you follow the low side of the recomendations on the botttle. ( i use the .7 conversion factor so you might get different reading on ppms thats why i always use ec cause it is universally right and the same no matter who measures)

any way that what you are doing with it at like 200 is good id go to like no higher than 150 with 100 being optimal. becaue the point of ro filters is to get high ppm water down but it strips it totaly the goal is to mimic perfectly balanced tap water that is around 75-100 ppms. 200 is considered not good and in need of ro filteration. cause you dont know what the ppms are ( minerals like mag and cal, etc.) but with the sensical its a perfect balance of all micros.

as far as you ph dropping like that over a 4 day period that is perfectly normal. as long as they stay stable for at least a day there is nothing to worry about just keep and eye on ph and ec. the solution is going to flux no matter what even if ed rosenthal was using dwc buckets. it normal for it to do and that much of a flux over a 4 day period is common. thats why they say you should check at least once a day and adjust i used to check every 2nd day and it always needed adjusted now if you set you ph at 6 and like 4 hours later its at 4.5 yeah somthing is not right.

your plant look good right? probably so.

this is why they say hydro is more finicky and less forgiving cause if you get lazy and dont stay on top of resorvoir conditions shit will go south quick. try to every day or at least every 2 days check it and adjust. only other option is to grow in soil and that still needs periodic monitoring. i check my soil ph ever 3 days sometimes every day.

ph flux is normal it means plant are growing and it should usually flux upwards if not like stitch said they are getting to high of ppms right now once you get the ppms dialled in there wont be much of a flux at all. they will take the solution in equally nutes and water, and not just one or the other

when i use to do hydro i fucked up a lot in the beginging cause of following what people say about ppms like the plants should be getting this or that much one guy says 1200 other says 1500 and some say 1800 and even some say not more than 1200 with 1200 being the max.

in dwc buckets id give them no more than 1.1 ec ( 770 ppms @ .7, or 550 ppm @ .5)

i use to run my flood and drain at 1.0 in veg and 1.4 in flower. and thats caue it ws recirculating and they could use the higher ppms of 1.4 like you buckets are recirc. to

when i use to run a top feed drain to waste i never went abouve .7-.8 in veg. and 1.0 during peak flower, caue they always were getting a irrigation of well balance nutes any time i went abouve what i mentioned they got burned and burned good.

recirculation system EC: mid veg .7-.8 ec
mature veg 1.0-1.2
early flower .9-1.1
di flower (peak) 1.2-1.4
late flower( nearing harvest) .5-.7

open end or drain to waste system EC
mid veg .5
mature veg .8
early flowering .6-.7
mid flower (peak) .9-1.1
late flower . 7 or lower gradually lower nearing harvest

 

[MynameStitch]

Most RO water is stripped everything, I have never seen RO water more than 20.... if you have 100 to 200 ppm your RO filter needs changed or your RO system is busted.

RO filters out ALL minerals and any bad crap in the water.

Another thing, I know sensi cal is great to use, but if your pH is off or something else like off gassing of vinyl, those nutrients WILL BE LOCKED out if certain conditions are met, I don't care how much care you give them, if there is something that is causing an imbalance and does not matter how much sensi cal you give it, it will still be locked out untill the conditions that is causing the problem is fixed.

Ya, I will agree with you there, those ppms chart is an estimate, some like more some like less, you should always go by the plants, what the plant likes is what you give the plant. Taller bigger leaves plants needs more food, you have higher wattage lights and plants got big leaves you can give slightly more food, stronger light makes the plant stronger and eat more food.

 

[Guest]

yeah stitch ive been reading those hydro hut post and have kinda been thining bout ripping down all of my black and white polly that i wave lining the floor up to a foot up the wall. cause it only like 5 months old. i get worried that i might catch some of the bad room syndrome.lol=not really very funny though.

 

[DIGITALHIPPY]

sounds like you should just water down your solution with 1/5 or 1/6 th parts water/solution....


imo.