Perpetual Harvest, what is it and is it worth it?

[Mac]

40% humidity in flower is ideal but not essential.

I regularly hit 70+% humidity in flower, My grow is in a downstairs room so cant leave the window open over night. Airflow is the key, keep ALL the air in the tent constantly moving and it should be fine, obviously its a higher risk but the reward is I don't spend 25 quid a week running the dehumidifier .

[GEORGE]

I haven't grown any Auto's to speak about, but all my Photos will make you look around for the Marshine.

[scoot]

A perpetual harvest can be both good,and a pain in the arse.
Like someone else said you end up with more jars(or grove bags) than you expected,plus constantly checking on the plants etc..
After my current grow I could easily stop growing for about 6 months before growing anymore and still have plenty.

[Farmer Geddon]

The only benefit I see to a perpetual is if the grower is always running dry between harvests. Then the dry spell is a matter of days, not weeks. Long term, it's going to be the same total of dry days. Use adequate grow space and running dry is a thing of the past, whatever the grow system or style used.

For easy maths, say 12 weeks from an auto being potted up to being chopped. 6 plants, a harvest every 2 weeks. 26 plants chopped every 52 weeks. Doing a simple grow and chop is 6 plants every 12 weeks. 24 plants every 48 weeks. Whichever way you do it, a plant needs to be in its pot for 12 weeks before it gets chopped.

An active hydro res that is too small for the lighting used will always be having ec/pH issues. Yield killer. A res that is larger than it needs to be will have no ec/pH issues. (Unless you are Determined to Do It Right!') Will cost a bit more in nutes used but will probably lower the growing cost per gram. Think of it as insurance.

I've only seen one shallow water culture grow that imo was worth copying. The Grow Tunnel by Keeef Treeez. (I forget how many Es in his name.) His Grow Tunnel cab got a lot of attention but his swc setup was simple as. A shallow tray, ~4" deep. In the middle, a 4" waste pipe fitted to leave 2" of water in case the pump failed, no dry roots. Fittings in each corner of the tray so the pump directed the flow at the corners, no standing water. The res was under the tray with a 16" drop from the waste pipe back into the res. That's enough height to kill most if not all of the bacteria. He also had soaker hose glued to the base of the tray with a largish airpump pushing bubbles through the soaker hose. Showerboard on top of the tray with holes for the netpots.

[Techead]

Hi V8, I'm assuming these are Photoperiods, that would make a lot of sense, with Auto's not so much, as the lights don't have to change, that's why I mainly grow Auto's, I also have three tents, one is too big, so is in a box, one is out of action during summer, the other one has a Gorilla Cookie Feminized Auto 'Clone' in it, Yup, I really have one, courtesy of my Photoperiod grower friend, who didn't believe that Auto Clones don't do well, that's 1 Metre tall?
Over the years I have bought and sold Privately Guitars, I still have 23 left, so I'll just sell a few and finance another waste of time and money, what am I like......

[Techead]

Hi Farmer Geddon, Interesting post, GHE actually give exactly the same reason for a Large Reservoir, Jeez. how many systems are there, Now shoot me if I am wrong but my logic states a very small reservoir topped up continuously, with fresh PH balanced Nutes, wouldn't suffer from EC/PH issues, because it will sort of be a supply on demand deal?
Obviously that flies in the face of the accepted norm, but I don't see why it wouldn't work, the mechanics of a sytem to do it would probably kill the deal though, thank you for your thoughts.

[V8]

Hi V8, I'm assuming these are Photoperiods, that would make a lot of sense, with Auto's not so much, as the lights don't have to change, that's why I mainly grow Auto's, I also have three tents, one is too big, so is in a box, one is out of action during summer, the other one has a Gorilla Cookie Feminized Auto 'Clone' in it, Yup, I really have one, courtesy of my Photoperiod grower friend, who didn't believe that Auto Clones don't do well, that's 1 Metre tall?
Over the years I have bought and sold Privately Guitars, I still have 23 left, so I'll just sell a few and finance another waste of time and money, what am I like......

Yupp photos. If I had a place to dry i would prob do autos but I dont do i have to dry in the same tent i flower in. But yeah. Good luck on your project sounds like you will knock it out of the park

V8

[V8]

Oh yeah. High RH is no problem if you have good ventilasion and air circulation. I rly pack my 3x3 full in flower. RH can sneak up to 60+. I say the higher RH you are working on the more fans you will need. 1 have 2 big once over the canopy. 1 big under with a small one pushing air up to the exhaust on the top. Will add 1 more small to help with that very soon. So its a hurrcane on there.

V8

[Farmer Geddon]

my logic states a very small reservoir topped up continuously, with fresh PH balanced Nutes, wouldn't suffer from EC/PH issues, because it will sort of be a supply on demand deal?

idk about having a small res but supply on demand is how the Dutch market gardeners do it. Their tech tells them how much of each mineral has been used and they get back to full strength using separate dry powder minerals. I'm assuming that they use RO water or else the tap water minerals not used by the plants will build up and cause problems. They won't be dumping a res that they have spent money adding minerals to.

Even if it were possible to get away with a 1 litre res by using a super dooper delivery system, the plants will still be getting what they need, can't cut down on that. A small res gives a one off saving over a larger res.

The lucas formula + RO water with auto top up can go the entire grow without a res change. Has been done many times. Some have pushed it to see how far it can go and they reported a build up of sludge in the res during the 4th grow. So 2 grows without a res change looks safe enough if the mission is to use the absolute minimum of nutes without needing fancy equipment. (Only an ec meter needed.)

5L of GH Micro and 10L of GH Bloom costs ~£100. Makes 2,500L of lucas formula. 4 pence per litre. Having a 100L res costs £4 to fill. £2 a grow plus whatever the plants use.

[Techead]

Hi Mac, I occasionally look at the Humidity, but don't actively do anything about it, whether its a dodgy reading or not IDK, but at present, it is at 44%, with one flowering plant in Dirt, I'm happy with that, I use an HTC-1, Clock/Temp/Humidity meter, probably not the best out there, but it will do, from memory, I don't ever recall the humidity ever being 70% though, but that aside and you have experienced that.it's actually a good thing for me to know for me. I think the only thing I would be concerned about though is Bud Rot, but I personally have never had that, so what do I know!. My tent has a good exchange of air and the Extraction system is on continuously, albeit not on full power, I use a Variactor transistorised Voltage regulator to control the speed, these are slightly more expensive than a conventional motor speed regulator, but the fan motor doesn't 'Knock' and make noise, which can happen with PWM controllers..
A very useful piece of info there Mac, thank you for sharing.