# First 2000W RDWC



## grodude (Feb 1, 2015)

I am getting ready for my first grow. I am planning on doing a grow journal on this site, but I wanted to run my setup by everyone to make sure I didn't make any mistakes before I get started.

I bought two gorilla grow tents. One veg room which is 4x4 and the flower room is 9x5. I have 2 1000w lights placed an even distance apart with 2 27 gallon totes underneath each light.
I purchased a hydrofarm 112w 110LPM pump with two 8.5" air stones per tote. I also purchased a 720cfm fan/filter/silencer.

I believe I will be buying a Girl Scout Cookies clone from a nearby dispensary. I read it should be a relatively easy strain to grow ( I figured I should learn all the same strain for my first grow so I can get the hang of it). I plan on vegging her to about 2.5ft and then using a scrog. I will be fimming, lsting, and super cropping as well. I will be feeding using RO water and the lucas formula. I have decided not to use calmag as I do not fullly understand if it is necessary and will buy epsom salt if needed.

The plan was to use these bulkhead unions, two per bucket, and use 3/4" pvc. I will also be getting a chiller (haven't ordered it yet). I also have the ecoplus 185 submersible pump.

[ame]http://www.amazon.com/Watts-PL-1872-4-Inch-Bulkhead-Fitting/dp/B0086DDRWG/ref=sr_1_1?ie=UTF8&qid=1422827199&sr=8-1&keywords=bulkhead+union&pebp=1422827222479&peasin=B0086DDRWG[/ame]

If I forgot to mention something please let me know, Also, I would be more than happy if other growers had input for me. I am very receptive to constructive crticism. Thanks!


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## grodude (Feb 2, 2015)

Any advice anyone?


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## The Hemp Goddess (Feb 2, 2015)

You will *need* to use Cal-Mag, especially with RO water.  This is not optional and Epsom salts will not work in hydro like a cal mag made for the purpose.  You cannot just forget an important nutrient that cannabis needs to grow because you do not understand it.  Hydro IS difficult and you cannot take shortcuts like this.  If you do not know, then you need to learn.

You are also going to need a pH meter and a ppm meter, pH up and down, and calibration fluids for both meters.  

I advise you to pick one training method and try that.  Learning to grow without getting fancy is going to be tough enough, especially starting out with something as ambitious as a 2000W RDWC.  there is no reason to lst and scrog, and supercrop and fim.  Most of these methods result in the same end result and you do not want to stress your plants.  

Take it easy, learn all you can. This is a long journey and a hundred different things can trip you up along the way.  There is a learning curve to this growing thing, especially with hydro.  A RDWC is going to be tougher yet.

I doubt that those bulkhead fittings are going to work well on a bucket.  A bucket is round, they are made for something flat.  Maybe using totes with flat sides (and a larger volume) would be better for a RDWC.  I think that larger volumes might be better also, maybe 10 gal totes per plant.


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## grodude (Feb 2, 2015)

The Hemp Goddess said:


> You will *need* to use Cal-Mag, especially with RO water.  This is not optional and Epsom salts will not work in hydro like a cal mag made for the purpose.  You cannot just forget an important nutrient that cannabis needs to grow because you do not understand it.  Hydro IS difficult and you cannot take shortcuts like this.  If you do not know, then you need to learn.
> 
> You are also going to need a pH meter and a ppm meter, pH up and down, and calibration fluids for both meters.
> 
> ...



I did ask about the calmag multple times and like I said there are experienced growers that are as firm as you in their opinion that say both things. This is not me taking a shortcut or trying to save $20 after spending so much, but I have had many people tell me it's not necessary, so I figured I'd use it if I saw an issue.

You make have missed it, but I am using two 27 gallon rectangular totes. They are not round. I actually found something cheaper and is 1.5 in instead of .75 in. Would this work with my 27 gallon totes? Can my resevoir be a 27 gallon tote as well or does it have to be larger?

[ame]http://www.amazon.com/gp/product/B00CG4F2V0/ref=gno_cart_title_0?ie=UTF8&psc=1&smid=ATVPDKIKX0DER[/ame]

Also, I do have the PH up/down, ph meter, ec metter, and a device to measure water temperature. 

Could you possibly try to explain to me why some say to use calmag and other say it isn't needed? How much should I be using? Does it matter which calmag bottle I buy? Thanks


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## 000StankDank000 (Feb 2, 2015)

X 2 I am also confused on this cal-mag thing. I was Told it is not needed in soil grows but hush puppy says it is. Now I'm using RO water and THG says cal-mag is a must. I'm confused. Can some one explain to us Thanks


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## Growdude (Feb 2, 2015)

000StankDank000 said:


> X 2 I am also confused on this cal-mag thing. I was Told it is not needed in soil grows but hush puppy says it is. Now I'm using RO water and THG says cal-mag is a must. I'm confused. Can some one explain to us Thanks


 
No person can tell you if its needed or not, its the plant that will tell you.

I do agree RO water will probably need it but your nute choice is going to have a lot to do with it as well.

And unless you have soil analyzed your not going to know if its needed or not.


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## skyhighatrist (Feb 2, 2015)

Calcium and magnesium is present in normal tap water and depending on the concentration of this and other elements depends on whether your water is hard or soft. RO water is just plain water - No calcium, No Magnesium, Just water.

Now every plant that grows has different needs and you should have bought nutrients that are specifically made for hard or soft water. The difference being one will have extra calcium and magnesium compared to the other. 

Now once you hit are on the third week of veg, most plants will want an extra boost. RO water has nothing extra in it so having cal mag (or in my case it's called cal.max) is going to be useful.

While soil does contain calcium and magnesium it isn't an everlasting deal and when doing hydroponics it's an absolute must, regardless of what water you use. 

Some people might say they never needed it because they've grow in soil, potted up into fresh soil to keep the food going then the plant hasn't needed more additives for a boost so it's not been needed. In my experience tho, it's always much better to have it and not need it, then to need it and not have it.

It also works exceptionally well as a foliar feed once signs of cal / mag deficiency show.


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## grodude (Feb 2, 2015)

skyhighatrist said:


> Calcium and magnesium is present in normal tap water and depending on the concentration of this and other elements depends on whether your water is hard or soft. RO water is just plain water - No calcium, No Magnesium, Just water.
> 
> Now every plant that grows has different needs and you should have bought nutrients that are specifically made for hard or soft water. The difference being one will have extra calcium and magnesium compared to the other.
> 
> ...



Thanks! Very helpful. So I should start using calmag around week 3. I read at 200ppm prior to adding nutes. What do you think of the rest of my setup? Am I missing anything?


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## skyhighatrist (Feb 2, 2015)

I don't fully understand how you're setting it up. Give me a sec to re read it all


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## skyhighatrist (Feb 2, 2015)

PH Meter. EC Meter. You can't do hydro without them!


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## skyhighatrist (Feb 2, 2015)

PH and EC can tell you what your plants are doing. Batteries going on phone. Be back in morning.


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## The Hemp Goddess (Feb 2, 2015)

I cannot imagine ever being able to do a hydro grow with RO waste without Cal-Mag.  If you are using tap water, maybe.  RO and hydro...not going to happen.

LOL--When you said you were using 2 bulkhead fittings per bucket in your first post, I believed that you were going to use 2 bulkhead fitting per bucket....

I do not do RDWC as I always have different strains that are different sizes that need different nutes.  But you are probably going to need a bigger res.  Someone who does RDWC will chime in.


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## skyhighatrist (Feb 3, 2015)

Yeah RO with no cal mag isn't going to end well no matter how good your nutrients are. 

While you're doing hydro, do you know how to tell if the plants need their EC increasing or lowering?


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## grodude (Feb 3, 2015)

skyhighatrist said:


> PH and EC can tell you what your plants are doing. Batteries going on phone. Be back in morning.


 I have PH up/down as well as an ec, ph, and temperature meter. Something new to me is the chiller. If I have about 90 gallons of water flowing, what do I want the rating of the chiller be. I saw one that was 13-100 gallons and was told is was not good for my setup and I needed something stronger


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## The Hemp Goddess (Feb 4, 2015)

You will need calibration fluids if you do not have them.

Exactly what kind of pH meter do you have?  Not all of them are good or accurate enough for hydro, which you really need to be able to measure down to a tenth accurately.  I do not use a chiller, so cannot answer your questions regarding the use of one.  I do not, however, believe that a 90 gal res is big enough for 4 27 gal totes.


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## skyhighatrist (Feb 5, 2015)

No it isn't!! 

You don't necessarily need to measure your pH down to a tenth of a point tho as long as you keep it in the range of 5.5 - 6.5. I've used the indicator fluid to do hydro with no issues like this. Not being argumentative, just opening some other options to you.


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## The Hemp Goddess (Feb 5, 2015)

Actually there are few nutrients uptaken above 6.0, so going above that locks out virtually all nutes, except N and Mg.  For that reason, hydro should really be kept between about 5.4 and 6.0 with about 5.8 being the sweet spot.

And I have had the opposite experience.  Using strips has never worked and always causes problems as they simply are not accurate enough.  It is quite hard to tell the difference between say 5.5 and 6.5, but a huge amount of difference in the uptake of nutes.  I, personally would never grow hydro without a good meter.


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## grodude (Feb 5, 2015)

The Hemp Goddess said:


> You will need calibration fluids if you do not have them.
> 
> Exactly what kind of pH meter do you have?  Not all of them are good or accurate enough for hydro, which you really need to be able to measure down to a tenth accurately.  I do not use a chiller, so cannot answer your questions regarding the use of one.  I do not, however, believe that a 90 gal res is big enough for 4 27 gal totes.


 How do you keep you water cool without a chiller?


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## grodude (Feb 5, 2015)

The Hemp Goddess said:


> Actually there are few nutrients uptaken above 6.0, so going above that locks out virtually all nutes, except N and Mg.  For that reason, hydro should really be kept between about 5.4 and 6.0 with about 5.8 being the sweet spot.
> 
> And I have had the opposite experience.  Using strips has never worked and always causes problems as they simply are not accurate enough.  It is quite hard to tell the difference between say 5.5 and 6.5, but a huge amount of difference in the uptake of nutes.  I, personally would never grow hydro without a good meter.



This is what I bought.

[ame]http://www.amazon.com/gp/product/B00HAKAFGC/ref=oh_aui_detailpage_o04_s03?ie=UTF8&psc=1[/ame]


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## Joe420Camel (Feb 5, 2015)

well, now you need to buy a Ph testing pen.  that is a TDS/Temp meter


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## Joe420Camel (Feb 5, 2015)

I use these two

the 2nd being the Ph pen

[ame]http://www.amazon.com/HM-Digital-TDS-EZ-Measurement-Resolution/dp/B002C0A7ZY/ref=pd_sim_hi_6?ie=UTF8&refRID=1MQTD4NHKTA5HXEJP1S2[/ame]

[ame]http://www.amazon.com/Oakton-EcoTestr-Waterproof-Tester-Range/dp/B004G8PWAU/ref=pd_sim_hi_24?ie=UTF8&refRID=1MQTD4NHKTA5HXEJP1S2[/ame]


as for chillers
I don't think THG runs a big enough setup to generate enough heat in the water and or has reduced the ways heat can get into the system
IE black buckets pull radiant heat from HPS lights
I need a heater in my (4 gal) res to keep it >66F in the winter


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## grodude (Feb 5, 2015)

Joe420Camel said:


> well, now you need to buy a Ph testing pen.  that is a TDS/Temp meter



lol I don't know why I read that does PH as well, thanks for catching that. Why is your PH pen so expensive? I've heard this is a pretty popular one. Will I have to buy calibration solution as well from the start?

http://www.amazon.com/dp/B00FJFEB2O/?tag=skimlinks_replacement-20


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## Joe420Camel (Feb 5, 2015)

error best caught early! 
nothing more frustrating than waiting till the package arrives only to realize the mistake and have to wait more shipping days

yes (7.0 and 4.0 I think) and storage solution although I believe some use one of the calibration solutions for both

biggest trick to them is keep the tip WET if its not testing the res, its being cleaned in water or its in storage solution.  

in hydro ph is E V E R Y T H I N G don't skimp on the one tool to measure it

I have a continuous readout (ph,ppm,temp) in my res and the ppm meter got caughtup in the roots and was partially up out of the water and giving false readings... came darn near nute burning/KILLing the entire crop (1 plant in my case)  
incorrect ph can be just as if not more devastating


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## grodude (Feb 5, 2015)

Joe420Camel said:


> error best caught early!
> nothing more frustrating than waiting till the package arrives only to realize the mistake and have to wait more shipping days
> 
> yes (7.0 and 4.0 I think) and storage solution although I believe some use one of the calibration solutions for both
> ...



Do I have to buy the oakton solutution or can I get this generic one? [ame]http://www.amazon.com/Atlas-Scientific-Calibration-Solution-Kit/dp/B007X5J9L6/ref=sr_1_3?ie=UTF8&qid=1423167030&sr=8-3&keywords=ph+calibration#customerReviews[/ame]  

Thank you so much for your posts by the way, I feel your input is going to make a huge impact on my grow. If there is anything else you see please let me know. I hope you can tune into my grow journal when I get that started in the next week or so.


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## Joe420Camel (Feb 5, 2015)

its all up to you if you trust generic (anything) 
[that stuff looks fine 2me]
most of the time I do but try to keep my "too good to be true" meter ON @ all times.


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## grodude (Feb 6, 2015)

Can I supercrop while scrogging?


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## skyhighatrist (Feb 6, 2015)

Yeah but you don't need to. The even canopy will boost yield enough without supercropping. I'd stick to topping and training mate.


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## skyhighatrist (Feb 6, 2015)

Saying that if you super crop the main branches just as they're hitting the screen then they'll grow outwards anyway which is what you want. 

It's up to you pal.


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## rickyjack9 (Feb 16, 2015)

chiller easy cheap way:
bought 40 dollar used mini-refrig, bought a 3/4 in round drill-bit thingy, drilled 2 holes in
right side, slid 20 feet of 1/2 in tubing into a hole, shaped it into a coil about 5 wraps
maybe, then ran it out of the fridge. I only use it to keep dwc water rez at 68. 
I use minimum setting and it gets too cool in winter. gonna be perfect in summer.
DWC requires 1. water at 68.  2. lotsa air. 3. 7-10 day rez changes due to dust in air. easy


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## rickyjack9 (Feb 16, 2015)

heater in winter?I guess a small heater on low voltage setting I find I need to keep growroom temps
at 65 or above. it has a thermostat, so only comes on when its below 65. that's the plan anyway. I have had to turn it down once but it seemed stable. im a beginner dwc but I know when the roots/medium get cold, growth slows below 60-65.
fresh air from outside can be cold but is fresh (co2) and needed.


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