RDWC Build guide

[Dirk-Diggler]

@badbillybobAre these going to use your spray bars as well?

 

Also what are flumes? and where is the best place to get the tank connectors and pipework?

 

Thinking of putting together a 2-pot system for a 1.2x1.2m tent but I am not sure my DIY skills are up to it, you do make it look easy though  

[badbillybob]

it is pretty easy to be honest. theres nothing much hard about it. 

If you can work a saw, some sandpaper, a tape measure and a drill, you will manage.

for a tent , I would use the really usefull boxes, 64 litres, 2 of them inside the tent and the res outside the tent.

 

 

the flumes are the pipes in the res which return the water to the top of the res, look at the bottom of page 3 in this thread you will see the pipes either side of the pump. thanks for reminding me about these, ill use them in  my new system

 

tank connectors are 40mm floplast solvent weld - ebay

rest of fittings and pipe is from the place that fixes screws.

Edited January 3, 2020 by badbillybob

[Dirk-Diggler]

Awesome thanks @badbillybobthink I will put a shopping list together, is it ok to run it past you here before I pull the trigger?

[badbillybob]

yeah sure.

I am using hose for the sprayers this time, the spray bars are a pain and have to be chopped out if you ever take the system down, so its gonna be hose with y pieces into the pots, similar to the yootoob vid V3 grow show I posted earlier. 

Edited January 3, 2020 by badbillybob

[Gomuningen]

I built and am running my first RDWC based on a Hygrohybrid D.I.Y build video that's out there somewhere. I modified mine to use 4 x 42L really useful boxes, as opposed to his use of two giant bins, but he has much more resources and space.

 

Anyway, building it was fairly easy, ended up buying myself a cheap circular saw, and wasted a bit of cash using trial and error to get the right type of pipes and tank connectors (Ebay is your friend, just don't confuse 2 inch pipe and 50mm for the same thing :)).

I went for a Hailea air pump with 10 outlets, so have two air stones in each bucket, and only one in the res (one of the lines on the manifold was broken, so I had to seal it off).

 

I went for the airstone option as I was concerned a little about the noise using sprayers (but my outtake fan and oversized-for-the-tent filter, kind of renders the point moot  

 

I bought a syncra silent 1.0 pump which I use inline so as not to affect water temps - The whole system is around 100 litres, and the pump copes well with it.

 

I also bought a cheap flip-top bin, and covered it in reflective foil tape (This was done at a later stage as I noticed Algae build up) for the res - Note: I covered the lids of the tubs in tape too after cutting holes for the net pots (hardest part as I only had a cheap dremmel to hand, it does the job, but you'll be smoothing the edges forever).

 

I'd just say be careful with your measurements, and don't skimp on the tools you'll need.

 

Finally, it helps if you can suspend the whole setup on very thick layers of something that absorbs vibration (I went for bubble wrap), my water pump buzzing can be heard downstairs, but it's low enough with the bubble wrap that I pretty much tune it out.

 

 

[badbillybob]

Sorry man I just seen this post...

 

It sounds like a nice system, any photos?

[Butterfingerz]

Wow!!

 

Have you ever thought to design from the ground up, contact a injection moldings firm locally and sell your very own designs. You could easily become UK420's go to member for RDWC/DWC hydro equipment.

 

I'm very sure we have some CAD/CAM type engineers and designers here that could assist, I know there is nothing better then to build your own but some members might not feel confident BUT I'm sure they would however be confident buying from you what with the images and experience you have.

 

Lovely thread!

[badbillybob]

Never thought about it to be honest...… im just a stoner f*cking about in my shed making stuff ha ha . I quite enjoy trying to track down fittings etc on the web, to suit our purposes.

I see alien etc selling systems for huge bucks, but most of that is grow shop mark up (a mate of mine used to have a grow shop and told me what he was paying for them- quite an eye opener), so i don't suppose Mr Alien himself is making a fortune...

i suppose i should maybe think about it, cos i really do need to earn some cash, im feckin skint - but wouldn't know where to start with injection moulding companies, getting fittings and pipe made to order etc, there's not too many options local to me to be honest. and postage wouldn't be cheap.

 

Might be an idea, but most people are tight arses, (like me), who don't want to pay someone elses wages if they can do it themselves.....but you got me thinking....

 

[badbillybob]

dissolved oxygen hydrogen peroxide and airstone bumf.

 

Dissolved oxygen (DO) 

ive mentioned this before briefly, but We all know that plants use carbon dioxide for photosynthesis and produce oxygen as a byproduct of that photosynthetic reaction.  plant roots must have oxygen. In a hydroponic environment it is essential to ensure your plant’s roots are supplied with oxygen. Growers using organic soils will never concern themselves with supplying oxygen to their plants; however, hydroponic growers like me must be well versed in the science of dissolved oxygen (from here on out called DO).

While most crops seem to prefer about 9 PPM DO, some crops like lettuce have demonstrated little to no difference in fresh weight or dry weight when grown in DO levels ranging from 2.1 PPM to 16.8 PPM . The low level of DO necessary for lettuce growth helps explain why the non-circulating Kratky method of hydroponic growing is so successful for growing lettuce. Absolutely useless for cannabis, but that's due to the low DO.  Conversely, some types of hydroponic systems require saturated or even supersaturated DO levels to yield vigorous growth, as is the case with NFT systems where ideal DO levels can surpass 40 PPM.

Dissolved oxygen levels in tap water are typically between 5-7 parts per million (PPM) at room temperature. Temperature has a powerful effect on how much oxygen can be held by water molecules. The warmer the water is, the less gas it is able to hold. Fully oxygenated water at 68° Fahrenheit will hold about 9 PPM of DO, while the same water at 86° Fahrenheit only holds about 7.5 PPM (over 15% less DO). It should come as no surprise then that the ideal temperature for maximizing root growth in hydroponic systems is 68° Fahrenheit, the temperature at which water naturally holds the 8-9 PPM of DO, which is the very amount of DO necessary to support vigorous plant growth in most crops. Water holds both dissolved solids like fertilizer as well as dissolved gases like CO2 & O2. The higher the PPM (dissolved solids), the less gases water can hold, so be aware that over fertilizing often occurs in conjunction with oxygen deprivation.

Common methods for increasing DO levels in hydroponics include adding concentrated hydrogen peroxide to the reservoir, powered aeration with air stones, and surface contact with atmospheric oxygen.

Hydrogen Peroxide

Adding hydrogen peroxide is a common practice used by many hydroponic growers but is one that is seriously misunderstood. There are 2 forms of oxygen: O2, the diatomic form which can be absorbed by the plant roots, and O2-, the free radical form which is highly reactive. Hydrogen peroxide (H2O2) converts to H2O + O2- when added to water. The O2- that is formed is not desirable because it will indiscriminately oxidize or damage healthy living plant cells. Also, although adding hydrogen peroxide to a reservoir will result in an initial boost in DO levels, those gains are short lived. Hydrogen peroxide is best kept in a grower’s toolbox for cleaning equipment and treating bacterial and fungal infections.

Air Pumps & Air Stones

Air diffuses into water whenever water comes in contact with air. This commonly occurs when water on the surface of a reservoir touches the air in a grow room or when air bubbles rise through a column of water in a reservoir. Many growers employ the combination of an air pump and air stone to add oxygen to their fertigation solution (the mixture of water and fertilizer). This is a viable option for many growers and one that is able to increase DO levels fairly inexpensively. An air pump pumps air through food grade plastic tubing to the bottom of the reservoir, where it is attached to an air stone. The air stone then diffuses the air into small bubbles which rise through the water, increasing the DO level as they rise. This also happens to be a great method for keeping one’s water and fertilizer mixed, preventing the fertilizer from settling to the bottom of the reservoir.

The size of the bubble that an air stone produces makes a significant difference in their ability to add dissolved oxygen to water. If a single large bubble and 8 small bubbles have the same total amount of air inside of them, then the surface area of the smaller bubbles will always be greater. Consider this example: a bubble with a 5 mm diameter has a volume of 524 mm3 and a surface area of 314 mm2. A bubble with a 10 mm diameter has a volume of 4,188 mm3 and a surface area of 1,256 mm2. The 10 mm bubble could be divided into eight 5 mm bubbles, which would have a combined surface area of 2,512 mm3. By producing bubbles that are half the size, the surface area is effectively doubled, doubling the surface contact of bubbles to water therefore doubling the capacity of the air to increase the DO level. Additionally, smaller bubbles are less buoyant and rise through the water slower, allowing them to diffuse more oxygen into the water. Smaller bubbles are produced by high quality air stones made from silicon carbide, which is fired at 1300 degrees Celsius. The high temperature produces a more porous stone which makes smaller bubbles than the less expensive blue air stones which are only fired at 200 degrees Celsius.

Air pumps and PH

Air pumps and air stones are not without their problems, however. Pumping air from inside a grow room, especially a grow room enriched with CO2, will cause the pH of the fertigation solution to drop over time. As air that contains 400 PPM of CO2 reacts with elements in the water like calcium, carbonates are formed which accumulate and lower the pH of the solution. Additionally, water holds on to some gases better than others, and because water can only hold a set amount of gas at a given time, the water molecules will selectively hold CO2 and allow the O2 to dissipate out of the water. Consider this example: if water can only hold 100 units of gas at saturation and it starts with 50 units of CO2 and 50 units of O2, then as air (which contains both CO2 and O2) is bubbled through the water over time, the water will absorb more CO2 and release the O2, resulting in lower and lower DO levels over time.

So are all hydroponic growers destined to kill their plants? If we add hydrogen peroxide then we oxidize the roots; if we bubble air through the water then we raise the pH and force the DO level down over time; even if we do nothing, when water stagnates (stands still), dissolved oxygen starts to rise from the bottom of the reservoir and dissipates back into the atmosphere. Don’t give up hope yet! There isa solution to our DO woes – adding a mixing or stirring pump to the reservoir. or manual stirring

Stirring Pumps

A stirring pump is a submersible pump placed at the bottom of a reservoir attached to little or no tubing that either continuously or on a timed cycle mixes the solution, similar to how the oceanic currents keep the water in the oceans perpetually moving. Mixed or moving water will allow the already dissolved oxygen in the water to remain stable in its concentration and also provide increased DO as the water mixes with air on the surface of the reservoir. Moreover, the movement of the water will prevent stagnation and reduce the potential of the growth of harmful anaerobic bacteria which cause unpleasant smells, toxins, and disease.

Although there are a few methods of increasing the DO level I have not touched upon like commercial air diffusers and electrolysis, these methods are not practical for most gardeners. In a nutshell, it is best to use the air stone and air pump combination for hydroponic methods like Deep Water Culture, and if you choose to use it in another type of hydroponic system make sure to place the air pump in an uninhabited, well-ventilated room that is not enriched with CO2. ive mentioned this before too.  (people hanging out in an enclosed space increases the CO2 levels). Dissolved oxygen levels in systems other than DWC are best maintained with the addition of a stirring pump. 

Or Fluming. I preffer fluming as its free and less effort involved

fluming involves the creation of surface tension disruption, by the use of crafty returns, into the res. . These returns on my own systems are angled 90 degree pipework, from the return pipe, aimed to wards the water surface.  This causes the surface water to bulge and creates ripples, increasing the surface area of the water and introducing more Dissolved oxygen than airstones or a 500l/min water pump. I am not running them just now, but will be again in future

[zen-ken]

 

[zen-ken]

Thought you would enjoy the video above @badbillybob

[badbillybob]

cheers Ken mate, ill have a look. 

[badbillybob]

yes, hes got the right ideas I would say, its been thought about, but some parts of it could definitely be improved.

the kinked return for the big pipes, to get it through the tent vent hole is effectively raising the water level for when its getting emptied, so you would only get about half to 2/3  of the buckets empty, but I can appreciate why he has done it.  a lot of people wouldn't want to cut the tent for a return pipe. I would, id rather cut a hole in the tent than empty out a hundred litres of water every time I changed the res....

the feed hoses as well, they would be better with a tee inside the bucket, but I suppose im being picky, its a good design and it would work well. 

it would deffo grow some trees though, and good luck to the bloke for putting it into production.

 

Thanks for posting the video @zen-ken mate, it will help those thinking about DIYing a system. 

[stu914]

43 minutes ago, badbillybob said:

cheers Ken mate, ill have a look. 

 

He won't be able to teach you much bud...even if you can stand his voice that is...

[badbillybob]

Quote

11 minutes ago, stu914 said:

 

He won't be able to teach you much bud...even if you can stand his voice that is...

I had it on silent, after about a minute...………..lol