Grow Beds - Fibre Glass.

[Murray]

I have had an email from yet another member about Fiber Glass Grow beds in regard to their strength and durability.

Fiber Glass is possibly the best man made material to use to construct tanks and grow beds for aquaponic use. (that is not to say that other products are not satisfactory)
Fiber Glass is strong, durable and is chemically stable. No leaching of nasty chemicals.
Fiber Glass is also dimensionally stable, unlike poly which is subject to instability especially in situations of large temp variations.
Fiber Glass is infinitely repairable. Should damage occur Fiber Glass products are easily repairable.

The boating industry has accumulated a large body of information on the durability and stability of fiber glass over 50 plus years intensive use. I personally have refurbished 35 plus year old Australian made glass boats and they are still out there giving great service. I think even the most biased person would have to concede that the operational stresses and strains encountered by a fiber glass boat hull negotiating a seaway, are far in excess of that experienced by a grow bed or fish tank sitting in a greenhouse.

There are now hundreds of my fiber glass grow beds (and dozens of tanks) in service on the east coast of Australia. All are confidently guaranteed.

A poly aquaculture tank.

[fishfood]

Yes i will go along with that 2 of my beds are fiberglass [ex hydro drug crop lift in a trashed house and holes kicked in them] $20.00 fiberglass repair kit [bunnings] and alls well the polly one I had to brace

[sillyoldfart]

Have no reason to suspect either fibreglass or poly tanks or growbeds have any long term detremental effects.

Do you have evidence that this is not the case with the use of UV stabalised poly tanks Murray?

P.S
The attached photo looks suspiciously like a saw cut to me

[Murray]

Gee, SOF, I must ask the farmer guy about the "saw cut" perhaps you are onto something there.
Perhaps it is a new "high speed harvesting" technique. "got to get those fish to market today"
Maybe he just "felt like doing it"
Maybe he was going to move it out of the shed and it would not fit through the door.

SOF, sorry about engaging in such merriment..........no, it is not a saw cut, It just plain broke.

Poly is unreinforced and therefore it relies entirely on thickness for strength. Bigger water tanks (from the better manufacturers) are very, very thick especially around the base where most of the pressure is.

The tank in the photograph just was not thick enough to handle the pressure of a full tank of water, I guess.

If we were to make grow beds, especially rectangular ones from poly, they would need to be very well engineered , especially if they needed to withstand the weight etc of ordinary gravel grow media.
It would be far safer to use only "expanded clay balls" or similar in such a grow bed. The media would need to be very light.
Also, It would be almost impossible to make a satisfactory rectangular fish tank of say 2000 ltr capacity, from poly

When we first started making our grow beds and fish tanks we had a few teething problems, until we got it right, so some people got some really cheap grow beds and tanks, VB was one fellow I can remember got some very cheap product.

Obviously round tanks/grow beds are much easier to engineer.

Why do we want to have rectangular tanks and grow beds instead of round ?
It is simple math......more effective use of available space...... and that is important to almost everybody, either domestic or commercial, but especially commercial.

Rectangular fish tanks and possible dead spots in the water flow within the tank.... now, that is another subject altogether.

See photo below of a 600 ltr rectangular poly tank. I still have one of these 600 ltr poly tanks that I use, but I have a steel frame built around it to hold it together. So it turns out to be too expensive an option in the end, the combined cost of the poly tank and the framework to hold it together.

[GaryD]

Hi Silly,

When can we expect some photos of your aquaponics system?

GaryD

[GaryD]

Hi,

Why do we want to have rectangular tanks and grow beds instead of round ?
It is simple math......more effective use of available space...... and that is important to almost everybody, either domestic or commercial, but especially commercial.

Rectangular fish tanks and possible dead spots in the water flow within the tank.... now, that is another subject altogether.

Here's the case for square or rectangular tanks:

• They're easier to cover.....and that makes them safer....and it simplifies the task of insulating them. Temperature is arguably the most important of the production parameters.
• They are more efficient in their use of space.
• They can more readily serve as platforms for other food production systems like grow beds or duckweed tanks.

For as much as 'dead water' might be an issue in large commercial tanks, it is no problem in small aquaculture tank of the type intended for backyard food production. The bottom of my fish tanks is cleaner than most any circular tank I've ever seen.....largely because I can cover them so I don't have a problem with leaves and other wind-borne debris blowing into them.

Gary

[sillyoldfart]

Hi Silly,

When can we expect some photos of your aquaponics system?

GaryD

Just as soon as I have all the bits together. Want to donate one of those you beaut fiber glass tanks or growbeds.

Help an old pensioner out Or do I need to be one of the inner circle or family to get a freebie?

[sillyoldfart]

Why do we want to have rectangular tanks and grow beds instead of round ?
It is simple math......more effective use of available space

Just on this question of space. Doesn't a square tank measuring 1m long by 1m wide take up basically the same space (actually slightly more) as a tank that is 1m in diameter? i.e 1m long by 1m wide???

[GaryD]

Hi Silly,

Pensioner? I thought you were a help-desk operator.

Comparing a 1 metre high X 1 metre diameter round tank with a 1m x 1m x 1m square tank is not comparing apples with apples. The round one holds 785 litres while the square one holds 1000 litres.

On the count of the amount of water that can be stored in a given space, the square tank is a clear winner.....and then there are all of the other benefits, too.

If members would like a very handy calculator for such things......here.

GaryD

[sillyoldfart]

Pensioner? I thought you were a help-desk operator.

How on earth did you get that impression Gary?

As listed in my profile "Retired Research Assistant".

Emphasis on "retired" mate.

Yep, obviously the respective height of either a "square" or a round" container will determine the relative capacity.

But I thought we were discussing "space" i.e the footprint area

Apples sure aren't oranges, but they're not bananas either lol

As to the amount of water (capacity) you can store in a relative area, then it all depends on the relative height of the respective container surely? The footprint is still the same.