135W Fluro in Autopot

Hey

Thanks for dropping by...

Am 3 weeks into flowering my sweet "Sativa"

under a 135W fluro, in an autopot, using Lucas 0/5/10

and have come across this...

Yellowing tips and some canoeing at canopy

https://www.icmag.com/ic/album.php?albumid=18716

Lowest 3 sets of fan leaves showing what seems to be Calcium Def (though starting from the bottom)

https://www.icmag.com/ic/album.php?al...ctureid=384253




Am wondering whether my addition of guano (hydroponic) has added too much K and locked out the Calcium...

Water temps range between 17-22C (62-71F)

Room temp = 18-27C (64-80F)

Light = 135 fluro grow light 7,ooo candles at canopy

Nutes = GH 0/5/10 (low intensity Lucas) @ 1.34 E.C. after guano added

pH fluctuates between 5.4 and 6.0

water = 100% distilled

Hi bob, I would back down the strength of that lucas mix as the tops are showing an over fert tip burn.
Considering the fluorescent lighting, they should do better at a weaker nute strength.
I would also add 1/8th teaspoon epsom salts per gallon for more mg, it's slightly lacking in gh flora series

hth

Cheers 10k

Some of the deficiency pics I've seen, tend to confuse, rather than inform!?

As, "apparently," yellow tips on new growth can also be due to lack of calcium...

Is this true?

Was thinking of going 50/50 distilled/tap for the extra calcium, as I hear salts can cause complications...

Any opinions would be greatly appreciated

You also arent giving any nitrogen which could yellow a plant, sorry I cant see the pics, says its not a valid link

Though lack of nitrogen does affect the lower leaves first, so I have to assume otherwise...

The Lucas formula does in fact have an adequate amount of nitrogen, and the pics seem to be viewable for 10K

Have gone with yr suggestion 10K

E.C. = 1.184

Also heard that it's best to have the pH around 6.0 for flowering

...especially around week 3

Does this ring true for anyone?