Leaves turning light green...again

[BAMWW]

OK thanks for all the advice guys. Pay day tomorrow so I'll see what products my local shop have. IIRC they didn't have any cal mag last time I asked

 

[Waira]

Bamm'-- ...I think you've got more than one thing going on here for sure,... noted your hard water, which equates to high alkalinity pH, and I'm wondering about your in-soil pH,... any treatment will need that info for sure, to at least determine if you have a pH lockout situation, or plain lack-of defc. problem; if it's a lockout, then adding more nutrients is not the way to deal with it, rather make matters worse... in fact, could go either, or even both ways, given how light you've feed so far-- I know- LOL!... symptoms I see: general paling of upper, newer growth-- likely an immobile nutrient, S is first suspect (Fe would hit newest growth hardest, different yellowing pattern)...best fix for that is epsoms (MgSO4-- 1tsp/qt), unless you have a dedicated micronute' supplement with S in it (best solution here IMO),... my worry is adding more salts into what might be some mineral salt build-up from the hard water-- again, that pH reading is critical,... The necrotic spots/patches look a lot like K defc., the dead spots at the "teeth" margins being typical, the more central dead patches less so, more like P defc.,... could be both, as at this stage, PK demands are at their peak! I don't see Ca or Mg defc. symptoms, and with water that hard, there's a lot of CaCO3 in there, and both Ca and Mg are robustly available under mild alkaline pH,... Is there some white-tan crusty stuff on the soil surface, stuck to the perlite, etc.? ..that would be mineral scale build-up, a sign of hard water minerals, and too much which can mess with nutrient uptake,...

 

[BAMWW]

Bamm'-- ...I think you've got more than one thing going on here for sure,... noted your hard water, which equates to high alkalinity pH, and I'm wondering about your in-soil pH,... any treatment will need that info for sure, to at least determine if you have a pH lockout situation, or plain lack-of defc. problem; if it's a lockout, then adding more nutrients is not the way to deal with it, rather make matters worse... in fact, could go either, or even both ways, given how light you've feed so far-- I know- LOL!... symptoms I see: general paling of upper, newer growth-- likely an immobile nutrient, S is first suspect (Fe would hit newest growth hardest, different yellowing pattern)...best fix for that is epsoms (MgSO4-- 1tsp/qt), unless you have a dedicated micronute' supplement with S in it (best solution here IMO),... my worry is adding more salts into what might be some mineral salt build-up from the hard water-- again, that pH reading is critical,... The necrotic spots/patches look a lot like K defc., the dead spots at the "teeth" margins being typical, the more central dead patches less so, more like P defc.,... could be both, as at this stage, PK demands are at their peak! I don't see Ca or Mg defc. symptoms, and with water that hard, there's a lot of CaCO3 in there, and both Ca and Mg are robustly available under mild alkaline pH,... Is there some white-tan crusty stuff on the soil surface, stuck to the perlite, etc.? ..that would be mineral scale build-up, a sign of hard water minerals, and too much which can mess with nutrient uptake,...

Thanks for taking the time the time to write that...it's a pretty comprehensive answer. I tested my run-off PH yesterday and it was 6.8. It was 6.8 going in as well so hopefully my soil PH is OK. I will adjust it to slightly lower from now on maybe and see what effect it has on the problem.

From the advice I received here, I foliar fed epsom salts twice a day for 2 or 3 days and I have got some Cal Mag to add with my feeding. I was only after watering when posting the problem so I only got to feed them with it yesterday morning. I also fed with bloom nutes and green sensation (a PK additive) at half strength.

The problem looks to have gotten worse over the following 2 or 3 days but it looks like it may have stopped spreading now. The unaffected leaves on other plants still look OK but the ones that were slightly yellow have gotten worse. Buds are swelling and they're starting to stink now so fingers crossed they pull through...

I will be adding the Cal Mag to the two younger plants from now on so I should have a definitive answer if they don't develop any yellowing.

 

[Waira]

..yeah, it takes a few days for thing to get in there and working, meantime, so some progression is expected,...some of the more hammered leaves may still tap out too, regardless,... we're not looking for any reversal here, just a halting, or at least greatly slowed advancing of symptoms,...Ahhh, a pH! huh, you know, under near neutral conditions and above, it's Fe that starts to lock out, and fast! -- this is why accurate pH readings are critical for diagnostics! S is robustly available under the same pH range,... have a look at the defc. picture depot, under Fe and S, and check out the pH availability chart too, pg. 2,... I still think it's S defc. behind the yellowing, but there's some overlap in symptoms,... this is why I recommend a good micronutrient supplement used for the entire grow, just for preventative measures,... the more immobile the nutrient is, the bigger a bitch it is to treat, and Fe/S are both immobile ones,...

 

[BAMWW]

Doh

Only just realised I should be adjusting my pH to 5.8 - 6.5. It was over a year ago since I did my last grow and had 6.8 in my head for some reason. I also had a look at the deficiences and it could well be a Fe deficiency. I've got some micro nutrient additive and will be using it from now on or at least until I get my pH back on track.

Anyway the girls are looking much better and I'm out of the worst of the trouble I think
This was the worst affected plant. Heisenberg at day 50

 

[Hal 8999]

Waira knows her shit. I would like to suggest you add fulvic acid to your growing. It will bring that ph down some and it is a chelate, so it will keep the nutrients in suspension and in a state they can uptake. It has allowed me to use Southern California's hard water with great results. I use the Earth Juice soy-Ful, it is what I can get. It is made from fermented soy beans and is rated at 0-1-0. Has a soy sauce scent, and you only use like an 1/8 to a 1/4 teaspoon per gallon.

 

[BAMWW]

Waira knows her shit. I would like to suggest you add fulvic acid to your growing. It will bring that ph down some and it is a chelate, so it will keep the nutrients in suspension and in a state they can uptake. It has allowed me to use Southern California's hard water with great results. I use the Earth Juice soy-Ful, it is what I can get. It is made from fermented soy beans and is rated at 0-1-0. Has a soy sauce scent, and you only use like an 1/8 to a 1/4 teaspoon per gallon.

I was nearly out of bloom nutes so I bought sebsi bloom a + b after a quick search led me to Tangs feeding schedule. I must admit I'm a little bit annoyed now that I realised it's not organic!

Still it might help with my pH and lessen the amount of pH down I'm using. My water is 8+ after bubbling!! If I need to reduce my pH further after adding the sensi bloom, will the pH down work or are the nutes somehow gonna buffer it to 6.5 (or whatever the actual figure is) no matter what I add to the mix?

 

[Hal 8999]

If you are doing organic you should be using citric acid powder as ph down, it also a natural chelate. You can get it where canning gear is sold and health food stores. Yes I do think the fulvic will help you get a proper balance again. The nutrient solution should only climb as the plants use nutrients.

 

[Hal 8999]

I do not know how easy it is to find in Europe, but I know Earth Juice grow 2-1-1 and bloom 0-3-1 is incredible organic hydro nutrients.

 

[BAMWW]

Good tip on the citric acid, I'll try that next grow. That earth juice isn't available locally to me anyway.

I can't decide whether to return the sensi bloom or not. I went to the bother of making a soil mix with guano and worm castings. Do the synthetic nutes kill off the organisms, etc that live in the soil?