Hi all,

I thought I'd start a thread about my own system, in the hope someone might be able to highlight potential problems I might encounter. Plus, it's a good way for me to keep track of my AP project.

The specs:
tank: 4500L (but initially I'll probably start with ~2000L of H2O)
growbeds: bathtubs (start with 4, can expand upto 12 in version 2.0!)
type: Flood&Drain (gravity drain from GBs back to tank)
fish: probably Silver Perch, hopefully some sort of crustacean.
pump: ?

Here's a picture of my AP site. This is where the GBs will be located. (See my layout diagram later.) In the distance, you can see the bathtubs.

There weren't many choices for AP site location as the land is very steep. Initially, I wanted to bury the tank (~500mm) in the corner, up against the house, but there was too much rock. (The whole house sits on a couple of giant boulders.) Then my better half suggested we locate the tank on the "cliff"! (Why do I think of the movie "Cast Away", with Tom Hanks? The scene where the portaloo washes ashore & he says "This could work!" with not much conviction.)

Anyway, that's what we decided to do. So, the next task was to level a site for the tank on the cliff ...

While I was levelling the tank site, I hit rock - D'OH! I tried to chisel it into submission with a crowbar, but ... well, let's just say the rock didn't lose. Replete with rage, I resorted to various instruments of destruction (including a drill), all to no avail. In desperation, I attacked it with a circular saw (using a masonry blade) ... yeah baby!! That saw carved through the rock like it was butter! A few taps with the crowbar & several iterations later, the rock didn't win! Yay! I'm smarter than a rock.

So the finished tank site looks like this:

I have procured some bathtubs to use as growbeds. I am plugging the holes up with ... plugs (permanently siliconed in).

How do you fit a 50mm (diameter) plug into a ~49mm hole? I soak them in hot water before inserting them - when the plugs cool down it is a nice snug fit.

Here's my first draft of the layout. Room for expansion, but not until I have a working system first. Bathtub dimensions are 1800x900mm.

Good base level starting point LOL

PS love the house location

Hi Scottie, welcome! Man, you have put some work into tank placement! Seriously, make sure that the retaining wall is ok with several tonne of h2o, I guess with the amount of sandstone there it is not a problem!!

Issues:

Plumbing! How the heck do I put it all together? Without leaks!
Do the water beds (bathtubs permanently filled with H2O, not gravel) need to be well shaded to stop algae growth?
Decide whether to use pump continuously or on a timer.
Design subsystem to handle power-failure.
Fish might be difficult to see against dark green walls/floor of tank.
Standpipe or autosyphons? (autosyphons easier to plumb but not as robust? a blockage could be catastrophic)
Allow system to expand to include NFT gutter (like KE14's system) in v2.0. (Need sump & extra pump? Hmmmm, might have to abandon this.)
How to plug the 60mm diameter hole in the bathtubs? (The 50mm plugs do not fit snugly, so will just silicon be strong enough?)
How to reduce gum blossom falling into beds & getting into system?
How to maneuver tank into position? I do not want the reputation of having made a rainwater tank fly! It's a looooong way down.

4.5t top be exact!

Are they new tubs? Rejects? Fell off the back of a building site? Plants will be real comfy in them

Yeah, will have to make sure the retaining wall is stable - I have visions of my fishies going on a sensory-deprivation ride, ala Homer Simpson.



Bathtubs are new, $7.50 each - got them from graysonline after a tip from skygazer. Hopefully the plants like an Ivory color.

Just fit a parachute to the tank...NASA probably have some ideas!!!
Wow, good price for the luxury growbeds! I believe plants only see in B&W, so colour not a problem. Looks like you have the makings of a good setup.

Just a question on your layout Scottie..... assume you growbeds are above your tank and will gravity feed back to the fish tank....

Sooo.... just what distance and head will you have to pump up to supply the growbeds by the time you factor the physical height and pipe length into the equation?

And are you just going to allow the water chestnut and yabbie tubs to overflow above a certain level to the two growbeds?