Water consumption in relation to harvest timing

[Brett Blaze]

Hi All

This is my first harvest and I'm trying to estimate my harvest schedule to allow sufficient time for flushing. I am fairly knowledgeable in regards to thrich coloration on the calyx to determine when to harvest but I was interested to find out if the sudden slow down of water consumption is an indicator as to when to start flushing and preparing for the harvest.

Throughout the flower stage it's been a steady 1 gal every two days. In the last few days that has dropped in half. Thrics on the sugar leaves on the top colas of the largest stems are 50% amber and the calyx is clear to just starting to cloud. Other colas (not as mature) still have clear to cloudy trichs on the sugar leaves.

Can the reduction of water be an indicator when to start flushing?

Less Mature Cola

Most Mature Cola - Sugar leaves turning amber while calyx is still fairly clear to cloudy.

 

[AngryBird]

I just read about that in Emilya's journal
@Emilya

 

[Emilya Green]

not knowing your growing conditions, a slow down in water uptake during the final bit of budswell indicates a problem to me, and definitely the need to flush. I am guessing that salts have built up from the heavy nutes in mid to late flower and are now restricting water uptake. I find it important to flush a synthetic nutrient grow right before the last two week period, so as to allow maximum uptake of water, and avoid what you are seeing here. Another week of heavy water usage and these things will be plump and ready to go!

 

[Brett Blaze]

not knowing your growing conditions, a slow down in water uptake during the final bit of budswell indicates a problem to me, and definitely the need to flush. I am guessing that salts have built up from the heavy nutes in mid to late flower and are now restricting water uptake. I find it important to flush a synthetic nutrient grow right before the last two week period, so as to allow maximum uptake of water, and avoid what you are seeing here. Another week of heavy water usage and these things will be plump and ready to go!

Thank you for your response. I actually started flushing two days a go with an expectation of around two more weeks before I harvest but wanted some input. I'm going to change the water out again today with fresh Ph'd water and continue for another 12 days or so. I will get some accurate water consumption rates today for the last two days.

 

[Emilya Green]

are you running a soil or hydro type operation?

 

[Brett Blaze]

This is hydro. Using Technaflora nutes. Technaflora

Currently at day 46 of flower and 60 days total. Recommended EC per nute provider is around 2.8 at this stage. I run closer to 2.5. PH is 5.8

 

[Emilya Green]

I think you are on the right track... I will be very interested to know what happens to the water uptake after this flush.

 

[Brett Blaze]

5:00 PM PT will be 48 hrs. I will post right after. Total water in the reservoir was 2 3/4 gallons 5:00 PM Wednesday.

 

[MrFortwenty]

The top of your bud in the one pic is totally bleached. Move that light

and

Irrigation Management Strategies for Medical Cannabis in Controlled Environments

Section 6.2 in a nutshell
"The practice of flushing is a current common industry practice but there is no evidence in published literature of its effectiveness in reducing nutrient concentrations within the bud or even whether or not this is a desirable result. After testing the nutrient concentrations from each treatment from three separate experiments, there were no significant differences in nutrient levels between any treatments within each experiment. This result showed that the intended purpose of flushing to reduce nutrient concentrations within the bud has no effect. These data show that for the last two weeks of the flower cycle for cannabis, it was possible to use no fertilizer water for irrigation with no significant impact on yield while saving input costs on fertilizer."

 

[Brett Blaze]

Bleaching occurred when the stretch exceeded my planning and was touching the LED. It has since been corrected.

This was after just two weeks of flower when the plant stretched over 100%. Considering the initial damage it turned out pretty good.

 

[Emilya Green]

The top of your bud in the one pic is totally bleached. Move that light

and

Irrigation Management Strategies for Medical Cannabis in Controlled Environments

Section 6.2 in a nutshell
"The practice of flushing is a current common industry practice but there is no evidence in published literature of its effectiveness in reducing nutrient concentrations within the bud or even whether or not this is a desirable result. After testing the nutrient concentrations from each treatment from three separate experiments, there were no significant differences in nutrient levels between any treatments within each experiment. This result showed that the intended purpose of flushing to reduce nutrient concentrations within the bud has no effect. These data show that for the last two weeks of the flower cycle for cannabis, it was possible to use no fertilizer water for irrigation with no significant impact on yield while saving input costs on fertilizer."

He is talking about flushing because of a drop in water usage... please, let's not start this discussion again.

 

[Brett Blaze]

He is talking about flushing because of a drop in water usage... please, let's not start this discussion again.

Thank you. My thoughts too.

 

[Brett Blaze]

Update: I replaced the water and removed 1 5/8 gals. Total water used in 2 days 1 1/8 gals so close to what I was seeing earlier. I’m going to continue to flush for about a week.

 

[morphin]

Hello mate.
I wondered how you took the THC picture on such a good scale ?
I'm terrible at it

 

[Brett Blaze]

Hello mate.
I wondered how you took the THC picture on such a good scale ?
I'm terrible at it

I use a 105 mm “Macro” lens on a Nikon D810 camera with a tripod. I use live view and manual focus. The subject needs to be abosolutely still and I use the timer shutter release to make sure there is no movement. A lot of paitience. And the most important thing. 40 years of practice.

 

[morphin]

I use a 105 mm “Macro” lens on a Nikon D810 camera with a tripod. I use live view and manual focus. The subject needs to be abosolutely still and I use the timer shutter release to make sure there is no movement. A lot of paitience. And the most important thing. 40 years of practice.

Thanks for the answer. I don't have a professional camera. I use 40x microscope with my phone camera. As you can see terrible results.

 

[Emilya Green]

I don't have a super expensive camera, but on these tight shots I have learned that a tripod and using the shutter timer is an absolute must. When I do that, the macro mode works very well, with the proper lighting that is.

 

[morphin]

I don't have a super expensive camera, but on these tight shots I have learned that a tripod and using the shutter timer is an absolute must. When I do that, the macro mode works very well, with the proper lighting that is.

Can you show me any picture of yours taken by phone camera?

 

[Brett Blaze]

I don't have a super expensive camera, but on these tight shots I have learned that a tripod and using the shutter timer is an absolute must. When I do that, the macro mode works very well, with the proper lighting that is.

Agree. Many cameras out there today that can do the job without spending a fortune. I just happen to have the equipment. Used to shoot shots of saltwater coral. The plants were actually harder to shoot. Here is a coral shot I did years ago. A lot of similarities.