Growing medium and ionic

[chip]

Hi all, more questions I'm afraid.

I have tried several different mediums (not Doris Stokes) while i've been growing, and i've just started to use rockwool again after using perlite for the last year or so. Before that i was using clay pebbles and cocunut shell, husk stuff! I was just wondering if any one has had any experiences, bad or good with perlite? I have changed because i cant seem to be able to stop a nute deficiency occurring in my crop.

I have been using ionic grow,  bloom and boost in flowering, which was a recent change after using optimum for a long time. I have also changed strains from NL5xHaze to Durban Poison. I didnt grow any NL5xHaze with ionic so i couldnt compare it with optimum.

The problem is that after i start flowering i get yellowing starting at the bottom. So i check the Ph. Solution going in at 6.0, coming out the bottom of the pots at an average 6.2. Then i flush them with Ph 6.0 water and then carry on feeding them at ec 1.6. Still no better. I tried upping the ec, but to no avail. I have started adding a small amount of grow/veg solution to see if it is a N deficency. I'll let you know how that goes. i have also started putting the solution in at 5.7, but still no change!!!

More details. 600w planta, humidity 45, temp, 28- 30 (a bit hot i know, about to invest in a cool shade or make my own the way DOC does it) Using sea of green technique, 4' x 4'  square pots, flowered at about 7 - 8'.

Is it because DP is a Sativa and needs more N to carry on growing in the way they do rather than like an indica? Do i need to up the nute strength? Is it the perlite and will my recent change to rock woll make any difference?

Come on 420, i need your help.

Chip

Keep it green, keep em keen

[Kif]

Hi Chip

Try lowering your ph,

ph for hydroponics needs to be lower than that for soil

it needs to be between 5.1 and 5.9 with 5.2 being the optimum. Anything outside this range can cause nutrient lockout.

Goodluck

Kif

[chip]

Thanks for your reply Kif.

I'll try lowering the Ph further, I must say i have my reservations, but I'll give it a go!

Any more comments on my predicament from anyone? What ec do other people use ionic bloom and boost at?

Cheers

Chip

[the d.o.c]

just thought i would point out that with a ph of about 5.2 you are limiting the available nutirents ,if you are having nitrogen defficiancy you want your ph slightly higher so that more of the nutrient is available to the plant

The recommended pH for hydroponic culture is between 5.5 to 5.8 because overall availability of nutrients is optimized at a slightly acid pH. The availabilities of Mn, Cu, Zn and especially Fe are reduced at higher pH, and there is a small decrease in availability of P, K, Ca, Mg at lower pH. Reduced availability means reduced nutrient uptake, but not necessarily nutrient deficiency.

hope this helps :thumbs:

the d.o.c

[chip]

As i thought. Thanks DOC. I am changing over to Rockwool. It just seems better. The feeding cycle that you suggested on another website (highlife) seems to answer some of my problems and give me a kind of basic base line. Does that make sense? Anyway cheers

Chip

[Guest THE PUFFER]

Can I just say, with all good intentions at heart...if you keep having nute problems, then the likelyhood of it being grower error is much more likely...honest, Im not being funny, but from what I know and have seen..that is usually the cause 90% of the time. Maybe a different regime should be planned or how you do it know, analysed and if needed, corrected.

:nervous:

[chip]

Thanks puffer. I am in the process of trying a different regime. So hopefully everything will be cool.

What would you reccomend i change first? I intend to up the strength of the bloom and boost solution sequentially over the flowering period. Starting at ec 1.6 and up to 2.4 by week 6.

Chip