Yellowing leaves.

[dlg256]

This starts to happen after about two weeks in flowering, see pic. I started using only RO water (thinking nutrient lockout) and minimum dosage of Tiger Bloom (2tsp/gal). The leave on the left is from 2 wk flowering and the other is from an older almost done plant. I still get decent buds, but something isn't right. Can anybody identify problem by looking at leaves. The room is not hot 75-85, and i only use dilute nutrients. Peters 20-20-20 during veg (about 1/4tsp/gal).

Thanks

dlg256 Reviewed by dlg256 on 12-08-2008. Yellowing leaves. This starts to happen after about two weeks in flowering, see pic. I started using only RO water (thinking nutrient lockout) and minimum dosage of Tiger Bloom (2tsp/gal). The leave on the left is from 2 wk flowering and the other is from an older almost done plant. I still get decent buds, but something isn't right. Can anybody identify problem by looking at leaves. The room is not hot 75-85, and i only use dilute nutrients. Peters 20-20-20 during veg (about 1/4tsp/gal). Thanks Rating: 5

[SwishaSweetz4Me]

Yeah mine is 35 days into flower and all my leaves are tunting yellow but the bud still looks fuckin good. Thsi natural. I was also thinkin Lock out. I add 2tbs/Gallon molasses. No Nutes at all. But was thinkin tiger bloom..

hope u get sum advice

-swisha

[polishpollack]

Why switch ferts? Because you want to use a "bloom" fert? The Peter's fert is fine. Check the Tiger Bloom to see if it has magnesium. Looks like either mg deficiency or the plants are just getting close to finishing, or perhaps a pH issue, but most likely it's because you've switched ferts for flowering. I doubt if it helps, and it might be causing this problem. Be aware that plants will yellow as they finish off. I don't know if using dilute nutes is good when the plants are large. You really need a ppm meter and take the Peter's fert to somewhere between 1000 and 1500 as they get bigger. somebody else might have good advice here for you, but looks like bad mg def. I think Peter's has mg in it already. If not you just throw in about a half teaspoon or so of epsom salts per gallon of water, and you can put this directly in the water you feed them; that will work. best of luck. post back what you do so people can see if it works or if I'm full of it.

[dlg256]

Thanks for the reply...I just checked and Tiger Bloom has 0.5% Magnesium...I switch nutes cause peters is too strong (I thought) especially for flower, and it has too much N. Also, I start out with dilute nutes (I was under the impression that good soil should have at least 3-4wks of nutes for the plant.) and move up as flower continues. Its just that this is already starting again, with dilute nutes in good organic soil. So no nut burn, no excess, and should be no deficiency. ??? Its a mystery. I'll just keep trying different things, I guess

Thanks for the suggestions...I will add some epsom salts to a plant or two and see what happens...

[polishpollack]

you can add epsom salts, but since the Tiger has some mg to it, I can't guarantee epsom will solve the problem. On Peter's strength, alot of people think you need to cut back the nitrogen and mabey that's true, but I know someone who grew alot of plants using Peter's 20-20-20 and never changed anything. You might try to determine if cutting back on nitrogen in flower is really necessary. Maybe it's not. since there is a good deal of yellow I wonder if the lack of Nitrogen might be part of the problem. Once you have something that works it's probably best not to change it. A ppm meter would be a good thing to have, meaning you can put around 1200 or so ppm in a water container and then water with it in soil. Just be careful you don't water too much. Let the soil dry up some.

[Weedhound]

Ever thought of checking your ph?

[dlg256]

Thanks again...The soil pH is just over 7. Maybe 7.2. The tap water I use is 6.3, and the RO water is 7.0. The soil pH changes very little. It does look like nitrogen deficiency, its on my list of things to try. I first lowered temp, then raised lights, then use RO water to eliminated dissolved salts, now I was lowering nutrients, so maybe next batch I'll use Peters only. I'll post back, after the results.

Thanks

[stinkyattic]

Use the technique described in the chemistry thread in my siggy to flush down to a corrrect pH of 6.7.
ONLY use RO water if you are prepared also to ADD CALMAG to 250 ppm before adding nutes.
That looks like overfert/soil salting, and you will need to flush and go to a correct bloom fert to finish.
Epsom salts should be used with caution. A general metlas lockout like that- grab some spray-n-grow next time you are at the hydro shop. The damage won't heal, but a correct flush and feed, and a light foliar spray, will stop it spreading.

[polishpollack]

Now that I look at the pics again, I think stinky is right about it being overferting. The leaf on the left is dark green where it's green and that's one more indication of overfert. I think the 2 tsps of tiger might be to blame. What the containers don't usually tell us is how often to give fertilizer.

[Rusty Trichome]

This is the nute schedule for Fox Farms:
FoxFarm Soil & Fertilizer Company

The schedule is a great way to 'dial-in' on your plants needs.

I use the Big Bloom, Tiger Bloom, and Grow Big for nutes, and Cha Ching as a late-stage additive.

Also, I nute twice a week, but with half-strength nutes. (combined total is same as one full weeks worth on the schedule)

Only difference between their FF schedule, and mine is that I only give half the recommended dosages of Big Bloom, and Cha Ching. I have no major gripes with the FF line, except the necessary flushes once a month to release the salts that build-up...but the results are great.