PH issues

[untamed]

i've bought some 'organic' potting mix and it seems I may be having some PH issues... its got added blood & bone and apparently lime to adjust PH.

i've been using it for a while with no issues, but all of a sudden, the mother and her clones are starting to show a slight MG deficiency..

I checked the PH of my water and its 7.0, at run off its 6.3, is this OK?

will epsom salts be OK for the MG def?

 

[greenisgold]

6.3-6.5 to me is perfect. That way you have a good buffer zone incase something goes wrong. Now some will say 6.5, 6.7-6.9. I find that if my run off is 6.3 my plants grow best. With the soil and ferts I use, if I add water that is 6.5, I can pretty much guarantee that my soil ph will be fine. I only check run off once every 5 waterings or so now.

 

[Maj.PotHead]

what are you checking the water's PH with a PH meter or PH test strips if a meter how long since it was calibrated. how long has the soil your having problems with now been in use, if 6-8wks type thing maybe the PH value in the soil fell through floor. and dolimite lime as top soil dressing would be in order. 2 teaspoon per gal soil the gently watered in. after a few waterings the plants should begine to recover, the new dolimite lime will help to keep soil stable little longer.

how much and how often do you water??
i like to water until it just begins to drain stop move to next plant, after all plants are watered i'll smoke a cig lol that allows proper time for drainage. then i move plants back and no water drops this also lets me feel the plants full watered weight. now each day i lift the container to feel moisture level when its light maybe 20-25% moisture left. i water again i dont like them too dry to where they droop or almost droop i freak when that happens lol. for all of veg most of flower my water is adjusted to PH 6.5 . late in flower i drop PH to 6.2-3ish i have a hanna PH meter digital disply 55$ cost great investment just calibrate it every month and it'll be spot on.

just outta couriosity what organic soil are you using ???
and are you using any ferts ??

 

[greenisgold]

late in flower i drop PH to 6.2-3ish i have a hanna PH meter digital disply 55$ cost great investment just calibrate it every month and it'll be spot on.

Many moons ago I read from a very seasoned grower, and I was amazed as well as others at the indoor pot he grew, that "he" made sure his PH was around 7 toward the end of flowering. I never followed this advice, but I'm just wondering about your reasoning to drop it to 6.2-6.3? Is this just based on you knowing that your soil has increased in ph toward the end, or is there something else?
Thanks

 

[Guest]

I think its cool getting down to the science of PH levels and all that, but if you are using good organic soil, your best insurance against leave damage is the dolomite lime as the Major said. I add the pellets to the soil in the recommended dose, and if the plants need attention right away, I grind the pellets in a coffee grinder and make a tea. Its usually stops leave damage within a day or two if it happens. My tap water isnt to bad, but the dolomite lime helps give me near perfect trouble free grows since I included it. I dont bother with PH level measuring anymore, but it is interesting.

 

[Blackvelvet]

Sure its magnesium (Mg) deficiency? You got a source of n, p, ca, and mg (if your mix contains dolomite lime and not something like calcitic lime with no mg only ca). You lack sulfur, potassium, and the micros...iron, manganese, zinc, copper, boron, and molybdenum.

You should add a high potassium fert like maxicrop seaweed or kelp to your water.

As far as ph goes...you need to test it the right way.

How to test soil ph using pour through (Virginia tech method): Water the plants till runoff. Wait 1 hour or so. Then apply a small amount of distilled water till you get about 1 ounce of runoff. Catch on a saucer or plate. Test this ph.

If your soil mix contains peatmoss, perlite, vermiculite, bark, etc... and not loam or clay soil, ph should be between 5.6 to 6.2 If 30% or more of your mix is clay or loam, ph should be around 6. (6 to 6.5)

If ph is low, you can apply some pulverized dolomite lime to the pot surface like Major is suggesting. 1 1/5 to 2 teaspoons per gallon of mix and water in. (3 to 5 pounds per 27 cubic feet )

If ph is ok or on the high side and your experiencing calcium and/or magnesium problems, you don't add lime. You can add cal mag to your water. (maybe 60 ppm ca and 30 ppm mg) Add 1/4 teaspoon calcium nitrate and epsom salts per gallon (3.8L) of water along with your regular ferts. Calcium chloride can be used instead of calcium nitrate. Its sold in bottles with names like tomato blossom end rot stopper. It will take the % ca and net weight of the bottle to give you a rate of about 60 ppm ca. "Store bought" cal mag plus could be used at about 7ml per gallon.

If your absolutely certain that you have magnesium deficiency, drench once with 1 teaspoon per gallon (3.8L) epsom salts. Severe cases might require 2 teaspoons per gallon. An alternative to drenching the soil mix is to spray once 1 to 3 teaspoons epsom salts per quart (.95L) on both sides of the leaves till it drips. Spraying ,however, does not supply the soil mix and roots with mag. Avoid spraying with lights on to avoid shattering the bulb. Once magnesium deficiency occurs it can be somewhat difficult to correct.



.

 

[untamed]

what are you checking the water's PH with a PH meter or PH test strips if a meter how long since it was calibrated. how long has the soil your having problems with now been in use, if 6-8wks type thing maybe the PH value in the soil fell through floor. and dolimite lime as top soil dressing would be in order. 2 teaspoon per gal soil the gently watered in. after a few waterings the plants should begine to recover, the new dolimite lime will help to keep soil stable little longer.

how much and how often do you water??
i like to water until it just begins to drain stop move to next plant, after all plants are watered i'll smoke a cig lol that allows proper time for drainage. then i move plants back and no water drops this also lets me feel the plants full watered weight. now each day i lift the container to feel moisture level when its light maybe 20-25% moisture left. i water again i dont like them too dry to where they droop or almost droop i freak when that happens lol. for all of veg most of flower my water is adjusted to PH 6.5 . late in flower i drop PH to 6.2-3ish i have a hanna PH meter digital disply 55$ cost great investment just calibrate it every month and it'll be spot on.

just outta couriosity what organic soil are you using ???
and are you using any ferts ??

lots of good questions here

its an electronic PH meter that was just calibrated.

soil possibly could be 5+ weeks old, growth has slowed a little also. I've also had a look, and I think all the clones have outgrown their 4" round pots, thy are approximately 8" tall. would this also cause slow growth, yellowing bottom leaves?

soil is a premixed soil, blood, bone & lime mix brought at a local store.. I wont mention the name, as I'm in Australia and you guys have way different mixes, so you most likely wouldnt know it. they claim it to be PH adjusted with lime already

watering is whenever the pots are light and tops are dry, however they are not wilting and thirsty - just right i'd say. never had an underwater/overwater issue.

ferts, I used to use them, however I havent tried any for a while.. heres what I was adding to the soil every other water and I seemed to have no issues with it:



is this any good?

 

[untamed]

Sure its magnesium (Mg) deficiency? You got a source of n, p, ca, and mg (if your mix contains dolomite lime and not something like calcitic lime with no mg only ca). You lack sulfur, potassium, and the micros...iron, manganese, zinc, copper, boron, and molybdenum.

You should add a high potassium fert like maxicrop seaweed or kelp to your water.

As far as ph goes...you need to test it the right way.

How to test soil ph using pour through (Virginia tech method): Water the plants till runoff. Wait 1 hour or so. Then apply a small amount of distilled water till you get about 1 ounce of runoff. Catch on a saucer or plate. Test this ph.

If your soil mix contains peatmoss, perlite, vermiculite, bark, etc... and not loam or clay soil, ph should be between 5.6 to 6.2 If 30% or more of your mix is clay or loam, ph should be around 6. (6 to 6.5)

If ph is low, you can apply some pulverized dolomite lime to the pot surface like Major is suggesting. 1 1/5 to 2 teaspoons per gallon of mix and water in. (3 to 5 pounds per 27 cubic feet )

If ph is ok or on the high side and your experiencing calcium and/or magnesium problems, you don't add lime. You can add cal mag to your water. (maybe 60 ppm ca and 30 ppm mg) Add 1/4 teaspoon calcium nitrate and epsom salts per gallon (3.8L) of water along with your regular ferts. Calcium chloride can be used instead of calcium nitrate. Its sold in bottles with names like tomato blossom end rot stopper. It will take the % ca and net weight of the bottle to give you a rate of about 60 ppm ca. "Store bought" cal mag plus could be used at about 7ml per gallon.

If your absolutely certain that you have magnesium deficiency, drench once with 1 teaspoon per gallon (3.8L) epsom salts. Severe cases might require 2 teaspoons per gallon. An alternative to drenching the soil mix is to spray once 1 to 3 teaspoons epsom salts per quart (.95L) on both sides of the leaves till it drips. Spraying ,however, does not supply the soil mix and roots with mag. Avoid spraying with lights on to avoid shattering the bulb. Once magnesium deficiency occurs it can be somewhat difficult to correct.



.

awesome advice, thanks.

 

[Blackvelvet]

Looks like your adding potassium and calcium with no magnesium. These 3 compete with each other. Its called cation competition. When you increase one, it decreases uptake of another. You may indeed have magnesium problems. I would suggest drenching the soil once a month with 1 teaspoon epsom salts per gallon of water when using this fertilizer. This in no way will harm your plants.

Helping out is no problem.

 

[untamed]

Looks like your adding potassium and calcium with no magnesium. These 3 compete with each other. Its called cation competition. When you increase one, it decreases uptake of another. You may indeed have magnesium problems. I would suggest drenching the soil once a month with 1 teaspoon epsom salts per gallon of water when using this fertilizer. This in no way will harm your plants.

Helping out is no problem.

I havent actually used that fertilizer for a while, thats why i'm just a little unsure of what the problem is.

they have had plain water for sometime as I thought the pre-added organics would help with NPK etc.

I will do a little more research and see if I can crack this problem, if not I will be posting pics pretty soon.

will plants that have overgrown their pot size show signs like I have?

 

[Blackvelvet]

will plants that have overgrown their pot size show signs like I have?

Yes...

 

[untamed]

pic from the mother plant, what is the problem with this plant in everyones opionion?



here is a pic of the same plant after a major cut back and trim:



pics of my "now" healthy clones... I upsized their pots and gave them a feeding of the above fertiliser, they seem to be doing great now:



close up of one:



these clones have heaps of pistils and they are in 24hrs veg, is this an autoflowering plant perhaps? is the amount of pistils it has a 'normal' amount of pre-flower??