plywood tables

no that's not shower liner, that is just paint shown in that pic. what I used is actually an air mattress that had a hole in the side of it, so I cut it up. its a little thinner than the shower pan liner but should work just the same.

 

I posted a diy with step by step pics about how I put it in the tray, folded corners. no glue

 

how much cash and time have you sunk into this project so far?

 

no cash, i'm a plumber so I got ALOT of fittings and pipe. the wood, paint and silicon I had from previous projects, time about 8 hours over 3 days. I would say probly about $100 in materials with the pan liner and all.


I guess that was a silly q about drip emitter, it was a thought I figured id ask.

 

I noticed last night that my plants weren't growing much. then I realized why, cold temps. I don't have a space heater so I have been counting on the 400 mh to keep everything warmed up. problem is, it was staying in the 50's and 60's in the room while it was in the 30's and 40's outside:icon_confused:. so last night I was thinking about this and kicked myself in the ass when I thought about my 1k m.h. yup the temps jumped up into to 70's in a hurry. I have a water bed heater under the res, but nothing to keep the roots in the table warmer than the room temp. hopefully the 1k bringing on the 70+degree temps is gonna change the growth issues. the roots do look nice and white though. what should the temps be in the root zone? is room temps in the lower 70's gonna be sufficient to keep the roots happy. I have never heard anyone talking about root temps in tables. I'm gonna have the veg room table done today and waiting for me to cut some clones. from reading other post I am going to switch from 6 hour flooding intervals to every 3 hours. it takes 8 minutes to pump 12 gallons (4") of nutes into the table, I let pump run for a total 10 minutes. should I flood it with less like 2 or 3 inches?

 

temp was 82 degrees on top of the table this morning(44outside), so I raised the light up about a foot. that brought it down to 78. the ac which is about 6 feet away from the light was reading 66. so I turned on a fan to circulate the air a little better than the a/c fan was doing I think the light shining down on the 1/4 inch painted plywood table top is gonna radiate enough heat through it to keep root zone warm. I went ahead and screwed the top down for the light leakage around the edges.

 

id pull that ressy heater out, that's the last place you want heat to be, unless the water is under 60f. as long as air temps are above 65 your roots will be doing great, also if you let it go below 63 or so during the OFF times, then your plants will drastically slow down to a crawl.....if you can keep your ON temps within say 8 degress of your OFF temps, that's the sweet spot for overall performance in a grow room...anything beyond that kills all the stretch and the plants motivation

 

I got the res heater set as low as possible @ 70 deg. I figured it would be better than 50-55 deg water(air temp) hitting the roots. it shouldn't come on anymore but i'll turn it off. usually the winters aren't this harsh around here. I need to get a little space heater to put out there for the night temps. i got the a/c set to come on @ 75. from what you said I would set the heater to come on @68.

 

just keep in mind that you want to be able to keep your OFF temps within 5-8 degrees of your ON temps, that way theres no "abusive" temps that will cause the plants to revert their energy into other places, you wanna keep the girls happy, which makes for happy roots, then happy producers, then a Happy Grown in Tex grower! know what I mean Gene???!!!!

 

right on CC :roffl: I did some temp testing today table top 78, root zone 75, res 68 and the a/c across the room reads 70. I mounted 2 of the 2 bank 4 foot flo's on the wall today @ 1 foot off the table to the bottom bulb just to give some extra light to the bottom of the canopy when they get that tall. not sure If I will need it but i'd rather have it up there if/when I do. the lights didn't cost me anything so wtf.

 

10-4 good buddy! roger!

 

And hey IDK about all of you guys, but since I have direct supply and connection to lab supplies for res temps I use freezer thermometers. Which is basically an alcohol based liquid vial with the probe inside. Now alcohol reacts faster with air temps because of specific heat differences, but works great with liquid based environments. Most of the thermos I use are suited for -20 to -80 freezers. Basically so the electrode doesn't freeze and give bad readings. But... alcohols have less of a specific heat than water, so when submerged in aqueous environments you get more sensitive readings, thought that should not be associated with timeliness. If in a water environment, the water will take more time to absorb energy than the probe. However the alcohol can detect those changes in the water faster due to it's change with temperature. I always liked that because EtOH based vialed freezer sensors for thermos work best in suspended aqueous environments.


Like this, even this "Thomas" unit is decent. I have one and they calibrate well with our biomed supplies at work. They are the same VWR ones we use on fridges that are not monitored real-time.


http://www.amazon.com/Thomas-Plastic-Traceable-Refrigerator-Thermometer/dp/B0069TGQPY/ref=pd_sim_sbs_indust_1

 

sounds expensive skunky