Get a harvest every 2 weeks

[lush1]

Can anyone point me in the direction of a square flood tray of the dimensions Al's talking about? (or near enough). Been searching for weeks and can't find one. Closest I can find is 36"x36" and thats cutting it a bit fine space-wise.

[lush1]

Also you say you harvest 21-23 plants per batch. As the trays only seem to hold 16 plants do you take some from week 3? or are there some plants in the week 3 tray that are actually in week 4?

[Al B. Fuct]

Originally Posted by lush1

Can anyone point me in the direction of a square flood tray of the dimensions Al's talking about? (or near enough). Been searching for weeks and can't find one. Closest I can find is 36"x36" and thats cutting it a bit fine space-wise.

Keep looking. Trays of various sizes are common and available at most hydro shops.

Originally Posted by lush1

Also you say you harvest 21-23 plants per batch. As the trays only seem to hold 16 plants do you take some from week 3? or are there some plants in the week 3 tray that are actually in week 4?

The flowchart depiction in the lead post in this thread is a simply schematic representation, not intended to show the actual layout- this is described in the accompanying post. Each of my 820mm^2 flowering trays will actually hold 24 pots but I usually only put 23 in them.

[haggis123]

Great thread, dude.
The ioniser you speak of, I can't see the pic of it anywhere...any chance you can put one up or a link to it ??
Considering going down the ozone route myself, but a bit scwptical wether they really do.....do the job and a bit worried on which one's would be suitable for our purpose and which ain't.

Keep up the good work.

[Al B. Fuct]

Originally Posted by haggis123

Great thread, dude.
The ioniser you speak of, I can't see the pic of it anywhere...any chance you can put one up or a link to it ??

Note hi-tech cardboard box light trap!

Considering going down the ozone route myself, but a bit scwptical wether they really do.....do the job and a bit worried on which one's would be suitable for our purpose and which ain't.

Ionisers are extraordinarily good at killing scents, so much so that if you run one in your flowering area, use a timer to run it in alternating 15min periods to avoid descenting buds while still on the plants.

There's 2 basic kinds of ionisers, those which use a fluorescent UV tube and those which employ high voltage between a couple of plates. The HV types also create nitrogen oxides, which when combined with moisture will create nitric acid, effectively acid rain on a very small scale. Use HV types only in the exhaust air stream, not in the room airmass with the plants.

Avoid the very small $20-30 desktop 'negative ion generators.' These are HV types but really don't make enough O3 for even very modest grows.

[haggis123]

Many thanks for the info Al, have been looking at the UVonair, same as yours but the smaller one.
Roughly, how big is your UVonair? I'm looking for as small as poss, it's for a micro grow.
You have yours in your garden and all is well....that's handy for a micro garden.

[Al B. Fuct]

Originally Posted by haggis123

Many thanks for the info Al, have been looking at the UVonair, same as yours but the smaller one.
Roughly, how big is your UVonair? I'm looking for as small as poss, it's for a micro grow.
You have yours in your garden and all is well....that's handy for a micro garden.

I have a Uvonair 5000 and a 3000. The 5000 uses a 14" tube, the 3000 uses an 11" and the 1000 uses a 6" UV fluoro tube. The housings make them all about 2" longer than the tube, but they all are in ~2" dia barrels with a 4" muffin fan on one end. The ballasts and ballast housings are all close to identical.

The operation manual in PDF for the 1000, 3000 & 5000 is here.

If you need precise physical dimensions with intent of fitting one in a tight space, you might inquire of Uvonair; I'm sure they can send you a dimension dwg.

[haggis123]

Many thanks Al.
You say there's a muffin fan in one end, is there any noise coming from this ??

Once again, many thanks.

[Al B. Fuct]

Originally Posted by haggis123

Many thanks Al.
You say there's a muffin fan in one end, is there any noise coming from this ??

Once again, many thanks.

No problem.

The fans installed on the Uvonair units are good quality, aluminium bodied units which run reliably and quietly, I haven't checked the labelling but I suspect they are ball-bearing instead of sleeve-bearing fans. As many years as my Uvonair units have been in more or less continuous service (about 5 years), they'd almost have to be BB fans.

[Al B. Fuct]

Cooltubes sorted.

Testing in mockup on the garage floor with 21C ambient intake air indicated that exhaust temp from the first lamp is 28.8C, a 7.7C rise.



This is an optimal figure, with only one lamp in line and no bends. I expect more rise in practise when installed. Some bends and squishing of the duct are necessary to make it fit.



If 29C air is then series fed into another cooltube, the exhaust air temp is about 34C.

The tube sockets are ceramic, so at those temps, I didn't feel too bad about running the tubes in much mechanically simpler series instead of parallel, nor be terribly pedantic about orienting the tube socket towards the airflow. Works.



I did opt for a closed loop, drawing cooling air for the tubes from outside the room's airmass and also dumping outside. Since it's closed, no scent control is needed on the cooltube air circuit. Got an Allvent 150mm axial pushing it for now, but I think there's a 150mm centrif in the future if but for lower noise. The axial will do the job for moving air through this system, but there's lots of bends and obstructions, noticeably reducing flow rate compared to other Allvent 150mm fans I have in use around here.



Input air during tests after installation was 22C. Output from cooltube 1 was 28C, output from #2 was 34C, rising about 6C for each 1000. I only tested it for about 15 mins as it's sposed to be nighttime in there now, but I'll get a look in later on when everything has properly started as usual and has been running for a couple of hours. I put a remote sensing thermo probe in the output duct to monitor the 'EGT' (Exhaust Gas Temperature for you non-jet jockeys ), as it were.



These cooltubes came with a built-in semicircular reflector which would have interfered with the batwings' even distribution pattern. Out came the tin snips and the built-in refs are gone.

The cooltubes' blower is on a timer, set to start at lights on but keep running for about 30 mins past lights off, assuring the lamps and sockets are dead cold before shutting down.

Of course, I expect my peak temps to be lower, but I'm especially looking forward to seeing what the RH does. If the main exhaust blower has to run less often because it's not solely responsible for removing heat from the lights, I bet I'm better able to control humidity. My dehumidifier is presently on a timer, set to run on lights-off only, but it may now be useful during lights-on. Without the cooltubes, the nicely dried air is blown right out because the heat from the lights triggers the main exhaust blower. Quite often recently, the intake air has been over 70% RH, and if the exhaust blower is running all the time, that's the RH in the grow room, too. I really want it to stay between 30-50%.

We'll see how we go!

[erockebomb]

How about a big round of applause for Al. After going through and reading this thread from start to finish, I have found the answers to all of my questions without even having to ask! As a first-timer this thread has been a lifesaver and your patience in answering questions(sometimes the same question more than once) is most definitely appreciated.

We're not worthy....we're not worthy

[Al B. Fuct]

heh, thanks for that.

The cooltubes have been in for close to 2 weeks now. Not really long enough to make any difference yet to the plants that are in there now, but the numbers are sure adding up better.

The improvement in stability of the room air temp with the tubes is simply astonishing. When the intake air was about 20C, without the cooltubes, the air temp in the room would wander up to about 26-27c. With cooltubes, the room air temp stays +/-0.75 degree C from the main exhaust thermostat setpoint. It's now set for about 23.7C and ye olde peak mem thermo sez it is staying between 23.0C and 24.5C.

The intake air has been about 18-20C @ 80-95%. The room's RH was only slightly lower due to warming from the lights- was running close to 70%- even with a dehumidifier, way too high. High RH was causing powdery mildew probs- saw a couple spots of grey mould on the buds, too. That's been solved- the RH is now between 55-60%, simply because the main exhaust is no longer responsible for moving the heat from the lights out of the room. The main blower doesn't have to run all the time, giving the dehumidifier an oppty to dry the air out a bit.

Can't recommend cooltubes highly enough. Can't wait for the first batch of plants to come out which have spent all their time under the cooltubes... that batch went in about 2 days ago- see you in about 8 weeks or so.

[VeoDigital]

Where did you get your cool tubes, all I can find is on ebay

[Al B. Fuct]

Got my cooltubes and 150mm axial blower from a local hydroponics supply house. Got the 150mm dia flexible duct at a local hdwe store. The aluminum flexiduct was astonishingly expensive ($40 for a 3m section, when fully extended), considering it is basically the same heavy alfoil material used to make disposable turkey roasting pans.

[haggis123]

Hi Al, just thought would give you a little up-date on my situation.

Thanks to your recomendation I went ahead and got me one of those Uvonairs.
I got the little Uvonair 100, which I think will be more than plenty for my micro-cab's needs.
It arrived yesterday, I plugged it in just to check what the volume level of the fan was like and just as you said...it is fairly quiet...which is what I was looking for....

I notice in your pic that you have a high-tech light trap (lol) over the end where the bulb is housed....I presume that this is necesary....for the dark period ??

I will post up some pics of my set-up when all done and dusted, this weekend hopefully.
Thanks for the recomendation.