Growbed with hydroton enough for filtration for DWS?

[BenHehle Beamz]

Hi,

My plan is to install a 1000 l IBC tank with overflow to a media grow bed and then to 4 floating rafts. Is it enough for filtration or should i install a swirlfilter after the media growbed to filter all the solids out? Any recommendations?

[Chris Schup]

Great information here—I’m working on a hybrid system design and also wondering about filtration. But, as TC said, it’s still experimental so the info comes in bits and pieces. Chris, have you shared component and plumbing diagrams of your hybrid system?

[Chris Smith]

No I have not shared a diagram of my system components because I don't have one and do not have the time to make one. My systems are continually being tweaked for maximum efficiency. My upper system I am constantly experimenting with new techniques to find out what works best for particular crops. If I made a diagram it would likely be outdated before too long.

I will be sharing a diagram of a new system I designed for a client but not until the system is up and running with no issues. That will take a few weeks at the earliest.

[Chris Schup]

Ah, well that’s understandable, thanks for letting us know. Good luck getting the new system in gear.

[Chris Smith]

I have hundreds of pics posted on my page to show some of my designs and configurations. There are pics of many of what I call integrated systems posted.

[Chris Schup]

Awesome. It’s been a while since I’ve checked your pix. Thanks for the suggestion.

[BenHehle Beamz]

Chris, awesome system! love it! do you have a picture of black cinder?

[Vlad Jovanovic]

If this helps anyone, here is a very simple block diagram (sorry nothing fancy) of the system I am still in the middle of building...The media bed to raft ratios are based largely on Chris' experience and suggestions (and some on Dr.Lennards calculator)...Though I tried to stick as close to Chris' suggestions as was possible. as far as I'm concerned, no calculator on Earth is gonna be better than real world experience...

Here's the deal...

96 sq.feet of slightly deeper than average (14" to 17") IBC grow beds and 568 sq. feet of DWC rafts.

One pump in the fish tank feeding the indexing valve.

Another pump in the sump tank... (I know, I know  not the most energy efficient, but hey, I can now pump "clean water" out to some vertical elements and some NFT as well as back to the fish tank at the same time, so not a total loss of electric brownie points  ).

I (and others) feel that a sane/low stocking density (it seems like many people over stock their systems with fish for some reason), as well as composting worms in the grow beds, will both play a key role as to how this 'hybrid' or 'integrated' system works out. I would add to this, a decent feed that wont create a lot of sludge might help too in keeping the solids down.

Oh yeah, each pair of beds is treated as a single 'irrigation zone' by the indexing valve. The valve is run by a repeat cycle timer.

 

[Bill Moore]

Here's something I have been wanting to ask.  Assuming a 4'x8' raft in a DWS, how many holes/plants will each support?  What's the spacing, center-to-center?   2 inch, 3 inch diameter holes?  Larger?

[Chris Smith]

Great system Vlad!  I am playing with airlifts to get clean water to towers and NFT instead of pumping. I agree that many overstock their systems. In my integrated systems I am trying to stay at a low stocking density of .3 lb/sqft. In my big tank that is very difficult though due to the size of the tank.

Bill there is a discussion in the raft/deep water growers group addressing your questions.

[Chris Schup]

Vlad, thanks for putting up the diagram. What size is your sump and what considerations did you make when calculating its size?

[Vlad Jovanovic]

@ Bill,

I think it really depends on what you are growing, and how big you plan to grow it out. I've used 2-3" spacing for seedlings/sprouts. I've had spinach and various salads using both 4" and 5" spacings and it gets really crowded quite fast depending on the particular cultivar. 6" to 8" seems to work better for most of the salads/greens.

Right now I have a couple different pepper plants in 3 different DWC set-ups, one of which has a 16" spacing and it's still not enough (actually it is now that I've pruned 'creatively', but barely).

[Vlad Jovanovic]

Well, mostly I was concerned with having enough sump capacity for:

1) The classic fish tank fluctuations...

2) When electricity cuts out, since in a worst case scenario would have 2 full beds that need to drain their full water load,  as well as 2 (previously full) beds that need to finish draining. Also, having extra capacity for whatever float valves to operate comfortably and be reachable.

3) (This was the biggy for me personally) It gets damn cold here, so in the winter I'd like to be able to by-pass the indexing valve and run a constant flow/constant flood scenario so that my grow beds don't turn into 8 massive heat sinks in reverse. So I needed to calculate for loss of electricity at a time when all 8 beds will then empty into the sump. If you don't ever plan on running constant flood, then this wouldn't be a concern.

Chris Schup said:

Vlad, thanks for putting up the diagram. What size is your sump and what considerations did you make when calculating its size?