Slowish growth Blue Kush.

Hi everyone.

So as the title indicates I'm having a problem of sorts. I feel as if my girl should be much bigger by now.. I'll give some specs on the grow.

Light: 250W HPS with a dual spectrum bulb in a cooltube
Distance: about 18cm/7inch from canopy
Strain: Blue Kush from Dinafem seeds
Medium: DWC, reservoir temps constant 66F, ppms at 740 and pH stable at 5.8
Extraction: cooltube is connected at one end to some ducting and that to a 250cfm fan
Temps: constant 24-27C/75-80F
Humidity: pretty low, I'd say 20-30% (although I did bump it up to around 50%, I'll know better when I get a new hydrometer)
Nutrients:GH 3 part flora series
Age: around 26 days...

Ok, so I was advised to lower the ppms, because I could have a problem with too much nitrogen in my reservoir. Some of the leaves on the plant are clawing in a little bit, not too much, but just slightly. Apparently too much N causes the plant to not grow so vigorously.
I was wondering if I'm doing it right, the ppms are now 480, so that's about 200ppms worth of nutrients. Maybe I ought to flush her with pH'ed water first for a few days?

I mean I was thinking it could be the humidity, but a lot of people wave their hand and say their girls do fine with low RH.

I was really hoping to break the 100g mark, but it looks like that won't be happening.

I really cannot afford to veg for a long period of time, but I would also want some decent quantity.

Thanks for any help/critisizm, all is welcome.

You can see the clawing in the third picture, overall she doesn't look too good, but that's me messing up the growth. She was growing nicely for some time, even with ppms as high as 780, but that's what caused the problem, I think.. I'm still not too sure.

How do the roots look? Does the rez smell?

Not at all, I change the reservoir every 7 days giving it a good scrub here and there. The roots themselves are white, but with a very slight brown stain (because of the nutrients, or so I have read). The aren't slimy or covered in snot and smell healthy as well.

I use GH, but run a modified Lucas Formula. If you cut out the grow, which many people do, run a 1:2 ratio of micro to bloom. Micro has plenty of nitrogen in it. I've run into the same problem in the past, so I don't use grow all the time. That's kind of hard to diagnose, They look like they are over watered, but that's not the case. Nitrogen toxicity usually forms a 'canoe' type shape.

Hmm.. I'll check out lucas method, but you're right, micro has A LOT of N, more than gro I think.

That's exactly what's happening now, canoing, despite the temps being low and the light in a cooltube (placed a bit back for the moment). Leaves crispy and clawing. Although I don't know if it's my hopes clouding my judgment, but I think the clawing is going away... I'll have to see tomorrow and compare.

Hmmm, is your water level a lil under the net pot or is it up in the stone medium? Are your ppms rising or lowering throughout the week, for example whats the week start at ppm wise and whats it end at? What ppm conversion are you using, hanna?

The water level is about a inch below the net pot.

The ppms themselves always were stable, so was the pH. I lowered them to 380 and today was the same value.

Unfortunately I have no idea what conversion I'm using, any way for me to check that?

I checked the plant today and I can't say anything has changed. Maybe it's too early and she needs time.

I've also been trying to find out a good product for preventing root rot. Something with beneficial bacteria inside. Great White and Tarantula are good I think. Anyone has any experience with anything besides hydroguard?

Maybe I should flush with pH'ed water?

Gregor Eisenhorn said:

The water level is about a inch below the net pot.

The ppms themselves always were stable, so was the pH. I lowered them to 380 and today was the same value.

Unfortunately I have no idea what conversion I'm using, any way for me to check that?

I checked the plant today and I can't say anything has changed. Maybe it's too early and she needs time.

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Got me puzzled, i'd say leave nutes set where they are for a week and see if it rides through this. If ppms have dropped after the week then up with more nutes, if they rise(which i doubt will happen at 380) then lower nutes. Don't top off the res for that week either just let it sit and drink.

You'd have to look at the manufacturers website of the ppm meter to tell. You know what company?

What size air pump are you using and how many air stones?

Unfortunately it's more of a no name, the company.

7.2l/min air pump connected to two long air stones, lots of splashing action.

I'll leave the rez alone like you said, but for now the ppms aren't dropping.

It probably all started when I started bombarding the reservoir with nutrients, maybe the plant will use up the nutrients it stored now and then will resume growth.

Gregor Eisenhorn said:

Unfortunately it's more of a no name, the company.

7.2l/min air pump connected to two long air stones, lots of splashing action.

I'll leave the rez alone like you said, but for now the ppms aren't dropping.

It probably all started when I started bombarding the reservoir with nutrients, maybe the plant will use up the nutrients it stored now and then will resume growth.

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Ohkay gotcha maybe check the listing of where you bought it, if you're in USA it's probably hanna. To convert from hanna ppm to EC you multiply by 2 and divide by 1,000.

Air is plentiful so yeah i guess just too high of a nute jump. Time will tell, good luck!

I'm actually in central Europe, the TDS meter was cheap, so it's not a Blue Lab/Hanna sort of thing.

Cheers Amon for the help, I might get some Tarantula for the roots and I'll be inspecting them for any rot.

Since your ppm meter is questionable, just try mixing 1 tbs (15ml) of micro and 2 tbs bloom in a 5gal pail. That gives me about 700 ppm in 200 ppm well water. That should be mild enough for most plants. Some plants can handle more.

Gregor Eisenhorn said:

I'm actually in central Europe, the TDS meter was cheap, so it's not a Blue Lab/Hanna sort of thing.

Cheers Amon for the help, I might get some Tarantula for the roots and I'll be inspecting them for any rot.

Click to expand...

Ohhkay yeah not to sure what conversion to use then. EC is just more universal so was trying to provide more clarity. Oh well

Welcome, wish i could help more but you got me stumped! Best of luck!

Update: no new growth from the top, but the altealternating nodes are growing so that is nice.

My ppm dropped so did my pH. 5.8 to 5.5, scary. Too little nutrients?

I'll add the same amount as last time and see from there how she handles it. Plants store excess nutrients yes?

Gregor Eisenhorn said:

Update: no new growth from the top, but the altealternating nodes are growing so that is nice.

My ppm dropped so did my pH. 5.8 to 5.5, scary. Too little nutrients?

I'll add the same amount as last time and see from there how she handles it. Plants store excess nutrients yes?

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What was the ppm drop and over what period of time? I like a little drop, can't always get it perfect and I rather it drop than rise.

Around 50ppm, so now it's 330ppm but that pH drop was serious, from 5.7 to 5.1 in over a whole day. I'll do a reservoir change now and add the same amount of nutrients as before.. maybe a little less.

Gregor Eisenhorn said:

Around 50ppm, so now it's 330ppm but that pH drop was serious, from 5.7 to 5.1 in over a whole day. I'll do a reservoir change now and add the same amount of nutrients as before.. maybe a little less.

Click to expand...

Good to see she's eating. If she ate 50ppm in one day I would say up nutes by at least 50ppm this time and let her sit and eat and drink for a few days, if PH changes just use some PH up or down to stabilize it.