Grow Beds

[B. Pearcy]

Originally I was planning to use a plastic goat / sheep tank housed in a metal frame for a grow bed, but with a little more research I am now leaning toward something like this polyethylene tank. The price is much higher, but overall I think it's better quality.

I'm not a plastics expert, but polyethylene appears to be a kind of plastic that leaches less in the long run versus some other types. It's used a lot for livestock watering tanks and in aquaculture.

I'm not familar with how polyethylene compares to fiberglass, but fiberglass tanks appears to be about 100% more expensive on average.

If I am calculating correctly, a 55 inch x 31 inch x 18 inch deep tank is 17 cubic feet (30,690 inches / 1,728 inches), but please don't make fun of me if my math is a little rusty.

What do you think?  Am I on the right track?

I've tried to find out what the 300 gallon Rubbermaid stock tanks are made from, but so far I've only been able to find "structural foam" as the description.  Anyone have any idea what type of material comprises "structural foam"?

 

[Chi Ma]

Those seem expensive. You can use these ones. Much cheaper plus they have a drain fitting.

 

http://www.tractorsupply.com/stock-tank-110-ga-2229862

[TCLynx]

The rubbermaid structural foam is HDPE I believe.

[B. Pearcy]

Thanks for the suggestion Chi Ma. At 36 inches x 52 inches x 20 inches that tank is a little bigger for a lower price.

[Sahib Punjabi]

I have also used the stock tanks from Tractor Supple and just purchased a few for Phase II from a competitor. I use the 40 gal tanks which cost $29.95 plus tax and I feel that they are better suited for my needs:

 

http://www.tractorsupply.com/livestock/livestock-equipment/stock-ta...

 

Yesterday I was fortunate to purchase 4 30 gal grow beds from a competitor (Tractor Supply were out of the 40 gal and would get them in a week or so), for around $25. Personally I would love to use the Fiberglass tanks but agree with you that they are rather expensive for a "Hobby Aquapon Farmer". 

 

Let us know what you end up getting :-)

 

God Bless,

[B. Pearcy]

Thanks for the information everyone.  I'll see some of you this weekend. I can't wait to see some real systems up close.  I think it will help me decide the final direction I want to take.

[Sylvia Bernstein]

We manufacture our systems with PE for the exact reasons you outlined, B.  It is the least likely to leach anything into the water, and you can get it UV stabilized and food safe.  The problem is that it is soft, and a rectangular shape is likely to bow without extra structure in either the shape, or a strap or support of some kind.  We actuallly looked at selling the product you show above as a grow bed and decided not to because it won't stand up to the weight of gravel with water moving in and out of the bed - a tremendous exertion on the long side walls...especially in heat.  Too flimsy, as are most hydroponic beds.  Fiberglass on the other hand is much more structurally strong and can handle that force.  That's part of what you are paying for.  Plus it's generally not manufactured in mass in China like the plastic containers above.

 

Structural foam is also very strong - think of it as an injected foam layer between two sheets of plastic.

[B. Pearcy]

Thanks again Sylvia for such timely information. There are no easy decisions it seems.

[B. Pearcy]

During the tour today, Sahib had a composite material in the experiment outside (from Sam's Club I think). 

I am trying to think of ways to be a little less obvious to the neighbors. Maybe plastic decking and a pond liner would work?

Sahib,

If you read this, what do you think about the decking?

I am still struggling with an "under the radar" grow bed design without breaking the bank. How about using the plastic composite lumber and making the bed longer and narrower instead of more square shaped?

Maybe paint some rebar, drive it down about 2 1/2 feet and use that for support, since the plastic lumber (Forever Deck or similar) will give a little over time?

[TCLynx]

I drove u posts down on either side of my raft bed.  Perhaps driving some longer U posts down on either side of the beds (before building them) would work for you (just don't hit any irrigation lines like I've done before after I got one of those great pipe pounder tools.)

[Sahib Punjabi]

Namaste B Pearcy Sir,

 

Thank you sincerely for coming to the 2011 Florida Aquapon Spring Tour. An amazing experience seeing so many Aquapon Friends :-)

 

I had searched for prices for material to construct the recirculating wicking beds. I wanted to create a "raised bed" that was at least 14 inches deep, 3 to 4 inches for rock/gravel fill and the rest for my experimental grow media. I have read that including Coir in this mix I should be able to get wicking to about a 12 inch depth. Any plastic composite lumber I found was priced around $8+ for an 8 foot length that was either 1/2 inch or 3/4inch thick and 4 inch wide. I would need 4 for each long side and 2 for each short side plus one for a center divide, hence 13 lengths in total...without any support lumber/re-bar or fixtures, I was looking at a total of $104 plus tax for one bed. The raised bed kit form Sam's Club, approx 7 ft 6 in long and almost 4 ft wide with a raised bed height of 7 inches was priced around $35 (last year I my friend had picked these up for $25 when they went on clearance...I will keep a look out if and when they do go on clearance). I stacked one on top of the other and had more than the height that I was seeking and did not have to spend any money on additional support or fixing materials.

 

B Pearcy Sir, Please let me know if you know where I can purchase the plastic composite lumber (Forever Deck or similar), cheaper and I will see if I can use that. I even looked at the plastic fence to see if I could break that up but not as economic. As far as being a little less obvious to the neighbors, that is your call :-)

 

Good luck...please share you experience so we can all increase our knowledge.

 

God bless,

 

 

[B. Pearcy]

My wife says I go overboard with researching stuff, but you might find this interesting if you're looking for grow beds.

 

Consider that 4 x 50 gallon Rubbermaids for grow beds and a 300 gallon Rubbermaid for fish tank = $489 from Tractor Supply

 

-and for comparison-

 

96" L x 24" W x 12" H fiberglass trough from Aquaticeco for a grow bed and a 200 gallon recycle polypropylene fish tank = $436

 

Understandably, the price of a stand to hold the 8 foot grow bed isn't included in that price, but for someone looking for that type of grow bed I was surprised that the price is almost competitive.

 

[TCLynx]

How do you figure the single fiberglass trough is comparable to 4, 50 gallon rubbermaid tanks?  The fiberglass trough is only around 100 gallons.

for any of them, concrete blocks are probably going to be the most cost effective stands for them.  I just spent lots of time the past two days looking at other options for stands and couldn't come up with anything elegant for much less than $100 for a stand.

 

Now I've been thinking that if one were unable to dig a stock tank into the ground, one could still probably get away with the 100 gallon stock tanks.  Just put them up one more level of blocks and don't drain them all the way.  Still get more filtration for just the cost of the additional gravel and avoid needing to build fancy stands.  It is ok to only drain the beds half way.  Outbackozzie has been doing !BC's full height as grow beds and he only drains his down half way.