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RDWC Build guide

86 posts in this topic
On 17/01/2019 at 8:43 PM, Zepharock said:

@SevernValleySavant check this out, is this the route you wanted to go with your next hydro system?


Yes mate, this was the original thread that inspired me. I've had some chats with badbillybob about how I'm going to go about this. 

Edited by SevernValleySavant
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12 hours ago, Warren cox said:

@Zepharock thanks for that mate..I checked my growtent for light spots last night and all across one stitched seam I can see all the pinpricks of light all the way along the side of the tent.. do you know if there is a specialist tape to cover  the said holes? Also thanks for the advice on slitting the holes for my res tubes... Is there a favourite strain for hydro growers that you know of? And with the profile pic, I'll change it now lol.. cheers bud.


If you think of a plants natural lifecycle in the wild, there exposed to moon and starlight. Light during the dark cycle can trigger a hermie, but I wouldn't worry that much, just prevent what you can. Im in the same boat, a little ocd, so i just used black gaffa tape in small pinholes on the outside of the tent. If you mean the seam where the zip is, I dont think thats preventable. I generally keep the room its in as dark as possible around that time.

Im currently growing a humboldt strain and seen some cracking hydro grow diaries for their seeds, cant go wrong! 


Checkout @badbillybobs grow diaries too, he grows exclusively in hydro i believe (Hence this topic :lol:). You'll get an idea of what to expect out of a system like this and see what strains a long time grower tends to use.

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4 minutes ago, SevernValleySavant said:


Yes mate, this was the original thread that inspired me. I've had some chats with badbillybob about how I'm going to go about this. It'll be 12 months away at this rate though. I'm only just starting my new job, after waiting 3 months for all the checks to go through. It's burnt a serious hole in my pocket.


If you need a hand building it i reckon we could wrap our heads around this.

Checks are a nightmare. A place I shall not name used to drug test randomly and you were out on your ass if you had the tiniest bit of cannabis in your system, yet the directors would be sat in offices snorting coke all day :unsure:

Positive vibes, you'll get there again!

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Just a quick update.

#Did I mention cleaning these systems out?

I cant remember and aint trawling thru pages to find out, so if I have, ignore this bit. 


Right your grow is down and you are swimming in bud, but it wont last forever will it, so best get cracking with another. Empty out the res and crack on yes...…..NO NO NO.

Empty out the res, but you need to clean it out, the whole system to prevent any chance of any possible contamination, bacteria, mould spores etc threatening your next lot. 

SO this is what I do, start by emptying out as many clay balls/ hydroton  as possible from the net pots.  You will be left with a huge root ball hanging off the netpot. Get a Stanley or retractible craft knife and cut it off, as flush with the net pot as you can. 

then remove the trunk/stem of the plant, and set the net pot aside. Take out the airstones and disconnect them from the hoses, and take the hoses all the way from the manifold off. 

Now, get the lids of the system as well as the airstones,hoses,netpots etc and dump them in the bath with plenty of bleach. Scrub scrub scrub, till you feel like a 1940's housewife...…, then take them out and leave them to dry. I run the hoses thru a bleachy cloth a few times, gets shot of any slime .


next up, fill the bath again with bleachy water and dump the hydroton in there for at least 24 hrs, mixing it all about and picking out any bits of leaf , stem etc. then fill the net pot with hydroton and rinse off with clean water. 

Once you've done al this, empty bath and  re-soak the hydroton in phd water, set to 5.6-5.9. leave them and check the ph next day and adjust accordingly.

When its stable, around 5.8 ish remove the hydroton and its ready to use.


You can change the airstones if you like, but I usually do around 2-3 grows and then change em out. I thoroughly bleach them in between. You can also put them in boiling water to disinfect them, but this seems to loosen the adhesive that holds the plastic male end and causes them to fall out I don't boil them anymore.

They get blocked with nutrient and gereral crap in the buckets and are less effective. They are only a couple of quid so why risk it.


Now the system itself. Empty everything out, clean the pump filters in clean bleacjhy water, then refil the system half way and add a good dose of bleach, id guess I used about3/4 of a cupful for 400 litres. then turn on pumps, and you will see why we only filled it half way, it froths up the bleach and you don't want it all over the floor (guess how I found this bit out lol) 

It should look a bit like thislarge_gr3.JPGlarge_gr2.JPG


The res doent froth, because its got no spray return, but you can see the buckets are foaming away. Leave it like this for about 4-8 hours, pumping everything thru the system. DO the chiller too, pump bleached water thru it, and if needed , change the chiller hoses. I do this every time. I use clear hose, cos it was cheap, but the amount of green algae build up is unreal. If you use black hose its obviously far less, but its still there. 


Now see the sponge in the pic above? use it to clean the inside and outside of the bucket, including the lids, and all the pipework, feeds and returns. this will remove or kill any mould spores etc. Mine was covered this time, but a quick wipe and its all gone.


After all this you should be ready for an emptying of the res and a half fill with clean water, then dump it and fill again with clean water and nutes.

put back the net pots half fill with the old hydroton and add some new, phd hydroton and your cuts seedlings an boom …..your ready for another fun filled water adventure. 

good luck

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@badbillybob hello mate wonderfull build! Got a few questions for a diy system i have in mind. Looking at using 60 litre euro boxs with 4 inch welded pipework and running a pump for suction on a reducing tee (got the idea from the alien rdwc pro). What water pump would you recommend? Also been looking at air punps and the rubber tube type air diffusers was thinking 1 a pot what air pump would be best suites or am i just being a moron hahaha 


Thanks dude

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you have missed a bit of vital information mate- how many 60 litre boxes are you running?

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Oh crap sorry mate i plan on doing 4 pot 1 res i like the look of the norres diffusers but not the price. Yikesss

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Oh and sorry for all the questions dude but in a 2m x 2m groom how would you lay out your system to allow working space (due it not being a tent) 


Many thanks billy your a legend

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Hi buildmeister...here's an idea for you to ponder on...


One good way to create DO in a system is fluming (of which I'm sure you're aware)...The problem with this is it introduces heat to the res and roots eventually tangle in the pump.

The roots issue is one that dogs RDWC especially in the return pipe to the res, this could help or even solve this. No spraybars to clog up and less joints and pipework in the build.


Have the intake from the res into the pots/boxes as close as possible to the bottom with a short right angle pipe facing upwards inside the res,

this would create the fluming bulge and efficiently oxygenate the nutes.


The return pipe would be located on the opposite side, again with a right angle pointing upwards.

To adjust the height of the nutes in the pots all you'd need would be a connector on the right angle return pipe,

cut several different length pieces of pipe which will fit into the connector, these can then be swapped to achieve whichever height is required.


Having the return above the level of the roots should solve the clogging problem or at least make it much easier to monitor and clear.

This would also automatically set the level in the res and because the return pipe comes in at the top of the res, help to oxygenate as well...


I'm sure there are flaws in this plan which I haven't spotted...thoughts?... (that's if this makes sense as it's late and I'm pretty baked)...:rofl:


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buy a carpet cleaner I just found out they work quite well if you have a little dwc accident  and non return valves for your airlines lol

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you don't need non returns for the airlines if you place the pump higher than the water level.


I would use a hailea aco air pump, they are really quiet. id be looking at a 60l/minute one for 4 pots.

I wouldnt bother with the diffusers, they are mega expensive and the golf ball airstones work just as well to be honest. plus the golf balls are much easier cleaned.

for a water pump you wont need much if you are running a true undercurrent system, like the alien pro system.  something like a maxijet 1000 would be plenty on a 4 pot system. if you over pump it it will just end up pulling the roots through the system/. 

if you can put a cleanable, removable filter between the big pipe and reducer, and it will help prevent blockages, if cleaned every few weeks.

id put the res outside the room if possible and run a chiller.

everything else sounds good. 

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