First Grow In Over 20 Years! Northern Lights Under 600W LED

[Homer Simpson]

Advice is only advice you do what you will with it! I know .... I’m stubborn as well haha!(so my fiancé says) but I I’m glad things are going well though! Any questions don’t hesitate to ask it’s what’s we’re all here for

Thanks, Dutchman; I appreciate the offer of future help and also for all the past help!!!

 

[Homer Simpson]

I have been trying to straighten out my calcium/magnesium deficiencies and since the consensus seems to be that my issue lies in my pH I thought I would try and test the pH of my runoff.

As you can see from the photo my runoff water is 5.3 pH which is much lower than the recommended 6.0 to 6.5 pH I am watering at. I have read many times to only be concerned with the pH of the water you water with but if my pH runoff is that low I can’t help thinking the water that is retained in the pot is even lower than 5.3 pH?

When I got my new pH meter and realized I had been lowering my pH too much and raised it my plants seemed to be doing better but the issue wasn’t resolved which makes me think I am still watering with water that is too acidic because my soil makes it even lower. I don’t know if this makes any sense to anybody but I am going to try watering for a while with neutral pH 7 water while testing my runoff to see if that improves things.

People may not agree with my reasoning but I am open to hearing any opinion?

 

[Pennywise]

What’s your RH and Temps running?

 

[Homer Simpson]

What’s your RH and Temps running?

My RH stays around 45-50 % with my humidifier running at the lowest setting and my temps are about 68F low with lights out with highs of about 76F with lights on.

 

[Pennywise]

Try running PH a little higher, 60%-65% is better than 40%

 

[Homer Simpson]

Try running PH a little higher, 60%-65% is better than 40%

Yes, I was going to try and run my pH a little higher as I monitor the pH of my runoff too. I have read that during flowering that the RH should stay below 60% and best is below 50% so I am surprised you recommend 60-65%? Do you recommend 60's % for late flowering stage?

 

[Pennywise]

40% is really low RH, 50% is ok during late flower.

 

[Homer Simpson]

40% is really low RH, 50% is ok during late flower.

Actually, that is good news because keeping it that low has kept my dehumidifier going pretty steady so I can save some hydro letting it go a bit higher. Thanks, Pennywise, hope you are enjoying your Sunday.

 

[Pennywise]

Been a decent day, cold and snowing but it’s Been ok.

 

[Homer Simpson]

Been a decent day, cold and snowing but it’s Been ok.

Cold here too, 18F right now but I just didn't go outside all day.

 

[InTheShed]

If you're mostly in coco/perlite you should flush it with plain water at 6.2 until your runoff pH is the same. Then the last gallon should be regular nutes at 6.2 so you don't starve anyone.

 

[Homer Simpson]

If you're mostly in coco/perlite you should flush it with plain water at 6.2 until your runoff pH is the same. Then the last gallon should be regular nutes at 6.2 so you don't starve anyone.

Ok, thanks Shed. I will give that a go tomorrow with my bad plants. I appreciate the advice. I really have to get my pH under control. That seems like a pretty logical solution to me.

 

[InTheShed]

 

[Homer Simpson]

If you're mostly in coco/perlite you should flush it with plain water at 6.2 until your runoff pH is the same. Then the last gallon should be regular nutes at 6.2 so you don't starve anyone.

Today I was pretty busy so I haven’t had a chance to take The Shed’s advice about flushing my plants but that did give me a chance to do some experimenting.

I tested the runoff from a second plant today and this one was 5.1 pH which is even lower than the 5.3 pH plant I tested yesterday. I am amazed it is this low because for over two weeks now I have been watering in the 6.2 to 6.3 pH range. Because the runoff pH had not risen after a couple of weeks of getting proper pH water it reinforced the sneaking suspicion I have had that my soil is causing my low pH instead of the fact that I feed my plant with too acidic water because I had a cheap in accurate meter.

So I did a test where I took tapwater at 7.8 pH and poured it through a sample of my fresh soil and it came out 7.1 pH so my soil did drop the pH pretty quick. Next time I tried a sample of 6.1 pH water and actually poured it into a container with new soil and let it soak for about a half an hour but this time it was the same 6.1 pH. I am going to let that sample sit overnight and tested again in the morning.

If it is still 6.1 pH then my soil is not the problem and somehow low pH must be retained after the water that delivered it has evaporated? Otherwise, I don’t know how to explain the fact that my runoff is very acidic despite the fact I have been feeding with the proper pH water for several weeks and the soil isn't the culprit?

So hopefully tomorrow morning my test sample is still 6.1 pH and if it is then my soil is not the culprit lowering my pH so then it must have been all the acidic water I fed it when I was using my cheap inaccurate meter has been retained somehow and hopefully a good flush will get me back in the proper pH ranges. Will report back tomorrow.

 

[MrSauga]

Well part of measuring the runoff is exactly for that reason. Find out what the soil is doing. Bringing it up or down. You may have to adjust it accordingly (higher) to get it in the range you want.
Others have more experience on that than me but at this stage I would still be pHing at 6.3-6.5. I know it's coco based but I think you're low. Go with the gut Homer...go with the gut

 

[InTheShed]

The best way to test the pH of the medium is a slurry test, not a runoff test. Runoff tests are complicated and I have the instructions from Cornell U in front of me!

The simplest and best is the SME method or slurry test. Distilled water is what you need, following these instructions...

SME Method:
The method that most lab use is called a Saturated Medium Extract (SME). This is a destructive method that you take samples from containers.
1. Wait 2 hours after watering plants.
2. Take samples of growing medium from several containers. Remove the upper ½ inch of growing medium and discard. Dig down into the core of the pot.
3. Take enough for about ½ cup of growing medium.
4. Place sample into a small plastic disposable cup
5. Using DISTILLED water, add room temperature water slowing and stir to make a mud. The sample should glisten on top
6. Wait 1 hour.
7. Calibrate the pH and/or EC probe
8. Place probe in the ‘mud’ and take reading. (Or use can use a coffee filter to drain off the solution to test)
9. Clean equipment after use and store properly

 

[MrSauga]

Exactly...

 

[MrSauga]

OK all you trichsters... what part of the plant is most likely to be ready first? If I want to get the most THC when cloudy, will the lowers be ready first or the upper colas?

 

[InTheShed]

I have seen it both ways though I don't know why it happens. Staggered harvest is the way to go if you want even ripeness and have the patience and the room!

 

[MrSauga]

I do for both... the lowers seem to have more whites compared to the tops, but those are the flarfs, and unlike my WW the lowers finished first, or the same as it was harvested at one shot. OK thanks!