Nitrogen deficiency?

[johnnyrotten]

I believe I have some 2-2.5 week old seedlings with nitrogen deficiency and some with nute burn.

The plants have coco starter cubes in perlite hempy cups. Had a 1/4 dose of AN PH Perfect on Sunday, PH is 6.3...

Temps are 78f and RH is 55%...

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[johnnyrotten]

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[johnnyrotten]

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[johnnyrotten]

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[johnnyrotten]

The plants have been under 4 22w 100w equiv CFL bulbs in the 5500 range. I added 4 more last night because and gave them PH 6 water last night.

 

[mckb024]

whats up johnnyrotten you may want to lower the ph a bit if your using a soiless medium, also the algae growing on the perlite can raise the ph as well. Other then that everything looks nice. good luck

 

[johnnyrotten]

Hey,

Thanks for looking at the plants!

Is algae growing on the perlite something to worry about? What causes that?

The plants were given the mild nute dose 5 ago and given water last night...

 

[vukman]

Hiya:
yeah, like mckb024 said....you should lower the PH if you're running a soiless medium. I don't run soiless but many of my 'associates' do ( I have very few friends)..
You can get all the info you need from the stickies in the soiless sub-forum and the algae, I'm sorry but when I don't know something, I just say I don't know....

Good Luck

 

[johnnyrotten]

I was hoping that the AN PH Perfect would eliminate the need to keep checking PH on this grow but it doesn't appear that way, possibly because the nute mixture was so low... I'll go back to checking it...

I've read on some hempy threads where 100% perlite is used that algae does form on the top and didn't cause any problems but I'm going to make some covers out of reflectix to prevent the light from shining onto the perlite and remove the perlite on top with algae...

When I transplant them, I'll be using a coco/perlite mixture... Hopefully, this helps with that...

Do the bigger seedlings look like they need nitrogen?

 

[SeaMaiden]

That does not appear to be algae growing on the perlite, but even if it is, it's not an issue in my opinion. If nothing else, when it dies off it will give up whatever nutrients are fixed in the tissues.

I agree with others that you need to drop the pH, into the 5's. If using coir, I like to keep a range of 5.8-6.2, allowing some occasional breaches both under and over that range.

They need more food, period. You can use urine diluted 10:1 water:urine. Free, won't burn, offers micros, and cheap.

 

[johnnyrotten]

SeaMaiden,

I was trying not to overfert them, so I underfed them instead?

I'll adjust the PH tonight to 5.8 and give them some food...

 

[SeaMaiden]

Yeah, that's the trouble using coir or other soilless media to start seeds in. Make your increases in feed very, VERY slight. Be aware that by just changing pH you may be changing the ability to uptake nutrients quite a lot.

 

[johnnyrotten]

I'm unable to change the ph in the cup without draining it... So, I'll drain everything, lower the ph of the nute solution, refill them and see what happens... I'm going to use the same strength in case the ph issue clears up the issue, so they don't end up with too much nitrogen...

 

[SeaMaiden]

Uh... don't the cups have holes in the bottom?

 

[johnnyrotten]

They are cups and have holes 2" from the bottom for a small reservoir...

 

[johnnyrotten]

They are using a hempy cup with the hole drilled 2" up creating a small reservoir...

 

[SeaMaiden]

I can't recommend that technique for seedlings. Just keep them in a tray and monitor the tray.

 

[johnnyrotten]

What exactly do you mean about keeping them in a tray? Do you mean that I should have kept them in the starter cubes in the tray? I moved them from the tray to the cup about a week ago... I guess I should have waited until later?

 

[hereigrow]

I agree they look hungry...I use a peat perlite mix ph around 5.8. In veg i also use 16 ml of AN sensi grow per gallon and they love it. They will turn around no worries bro. Good luck

 

[johnnyrotten]

Thanks for the info hereigrow... I used 4ml of Sensi A&b per gallon...
A 1/4 of what you used...