runoff on coco

[SkyLopes]

hi there, the runoff on my plants are around 7.3, a bit too high right? i give them nutes at 6.0 ... i dont know why it increases so mutch... what to do? do i need to flush them with water only? if so what ph is ideal for the flush?

couple plants are growing but all the leaves are yellow including young ones

thanks for your help everybody!

 

[Old Soul]

What kind of nutes are you using? Are they in veg or flower? What are your conditions like? Ideally, you want to keep the ph between 6-7 in coco in my opinion. But I use organics and never test my ph to tell the truth. If things are yellowing it could be a nitrogen deficiency.

Peace

Old Soul

 

[SkyLopes]

im using a local nute, it has every micronutrient needed... i know its not the best for coco but its what i have.. its decreases the ph a lot and i adjust it with ph up before watering the plant

 

[Old Soul]

are they in veg or flower?

 

[SkyLopes]

nute info

N (N) 8%
P (P2O5 solúvel em CNA + H2O) 9%
K (K2O) 9%
Copper (Cu) 0,2%
Zinc (Zn) 0,35%
Boron (B) 0,02%
Manganese (Mn) 0,02%
Chlorine (Cl) 1%
Magnesium (Mg) 0,6%
Sulphur (S) 1%
Cobalto (Co) 0,005%
Iron (Fe) 0,15%
Molybdenum (Mo) 0,005%

 

[SkyLopes]

they are in veg.. about 30 days.. my girl stole my camera so i cant take pics atm :/

 

[sproutco]

Stop using the ph up. Your ph is high. When using nitrate nitrogen(which is good), plants make the ph of the coco higher by releasing anions (negative ions) into it thus raising the ph. Lower ph has to do with the concentration of positive ions like hydrogen in your substrate. Here's the ph chart for mj. You would want your ph to be like hydroponics. http://www.icmag.com/gallery/data/500/91934936ph-nutrient_chart.JPG
Here's what you might use to adjust your ph: http://www.icmag.com/ic/showthread.php?t=31294&page=2&pp=15&highlight=sulfuric+acid

 

[SkyLopes]

if i stop using the ph up the solution will be too acid like 3.0 - 3.5 ... how can i stop using it? btw ph up im using is sodium carbonate

 

[sproutco]

Ph 3 to 3.5 is impossible under normal conditions. I think your ph meter is off.

 

[sproutco]

(first double post ever) Something is terribly wrong if you go from ph 3 to 3.5 and then to 7+ ph. From the list it appears that you don't have calcium in your nutrition. Magnesium at .6% compared to 9% potassium is too low. You want potassium to calcium 1.5-2:1 and calcium to magnesium 3-4:1 Yellow new growth=high ph especially lack of iron.

 

[SkyLopes]

no man... what i meant is that after i add the nutes to the water the ph decreases to 3.0 - 3.5 and i have to adjust it with a ph up solution before watering the plants.. i grow on coco.. i water by hand.. i dont have a reservoir.. im thinking about flushing it to try to fix the ph problem.. is that correct?

 

[sproutco]

From your list of nutes, you don't have calcium and your magnesium is low compared to potassium. Yellow new growth means high ph usually. After watering/fertilizing and the coco is wet, apply 2 or 3 ounces of distilled water(100milliters) to your pot. Catch the runoff from the drain holes. Measure this ph to get an idea of the coco ph. Stop adding the ph up for a time and see if the new growth doesn't regain green color. This is regardless of the ph. I don't think flushing with water is really the solution. Like I said before, ph 3 to 3.5 is almost impossible and your ph meter is off. Callibrate if possible.

 

[SkyLopes]

i have already added epsom salts to the plants and the tap water has calcium

im going to see if my ph meter is ok.. i calibrated it a month ago

 

[MTF-Sandman]

A good flush would be a wise start. The coco itself shouldn't be altering the PH much if any...I think all that sodium carbonate is building up in the coco causing your PH problems.

In the future you might wanna invest in some PH up/down that are intended for use with plants....

 

[SkyLopes]

i just checked the ph meter and i put it on the 4.0 solution and it came 3.9... i put on the 7.0 solution and it came 7.1 .. i think it is ok.. i dont know what you mean by ph 3.5 being impossible... thats the ph i have after adding nutes without the ph up solution... i dont know.. maybe im checking it too early after i add the nutes.. i will make a solution now and i will only check ph tomorrow to make sure of this

 

[MTF-Sandman]

If it's not reading what the calibration solution is, then it's not right. Adjust the calibration screws on your meter until it's dead on 4.00 and 7.01. For coco, you'll want to feed at about 5.8-6.0...and the runoff should be near the same. If the runoff is more than .5 off, then you've got some PH adjusting crap built up in the coco and it needs to be flushed out.

 

[sproutco]

Sodium carbonate is not the most desirable thing to use when trying to raise water ph. Carbonates can build up in the soil/coco as if it had lime in it. Sodium hydroxide or lye is really the preferred thing to use. Its reaction is infinite in that all of its "power" is completely used up immedietely with no lingering reactions that might take place. You will probably have to make a stock of maybe 1 teaspoon lye to a gallon of water. Then add some of this stock to your water after you have added ferts. till you get to maybe ph 6. Remember how much you used so you can repeat easily.

 

[SkyLopes]

thanks a lot for the help guys

 

[SkyLopes]

sandman.. my ph meter is like 7.1, 7.2 and so on... its is not precise like that

 

[MTF-Sandman]

Hmmm...what make/model is the meter? I'm starting to lean towards the meter being part of the problem...