Taking the next step

[jpcw]

Ok this Aquaculture stuff is addictive and should have a health warning attached . My 1000L system is sitting right next to a 40,000L pool and it keeps begging me to drop some fish in every time I feed the trout. So the question is how many people have gone that next step and jumped from a small pond in to a big pool?

I know that to fully service the pool I’m going to need some massive GB’s but if I wanted to build up to it should I be ok adding a couple of hundred fish as around 600-1000L of grow bed or is it really a case of all or nothing?

Are there any things I need to look out for when going with something the size of a pool?

One I can think of is how to stop the fish jumping out and stopping birds getting at the fish. It’s a bit harder to put a cover a 4Mx9M pool.

Or am I just doing my usual and biting off more than I can swallow?

[bunya boy]

JPCW,
I don't know if I should be disseminating this sort of radicalism or even thinking it's possible but, here goes . . . .

In planning our residence and surrounds, a small (800 litre FT/480 litre GB's) AP system has become an intergral part of the fabric and envelope of the Building itself. It is not portable or relocatable, even the little system GB's are part and parcel of the visual and structural envelope.
I have planned for a pool (which also forms part of the structure of the building (one wall of the pool provides the inherent anti-racking bracing for the house) which is 13 m long x 4 m wide and 1.2m constant depth. So this is about 62000 litre capacity. Because it is designed to incorporate a "wet edge", it requires a sump tank, in my case 11500 litre, to act as a volume balance tank. Return water is pumped back to the far end for recirculation. So far, pretty basic and achievable, normal hydrostatic valve in base, skimmer in balance tank, glass wier in end wall, ice tray for stubbies down one side, etc. etc.

But, . . . . I'm also putting in an 1100mm high dividing wall across the pool section to split the surface area into a 75 : 25 ratio. The 25% area will be sand and gravel filled on a slope from just above water surface level down to 1200 deep at the wier wall. This will provide my Bio-filtration when planted with various water "cleansing" plants of different heights and growing conditions to return clean, clear water to the swimming area over the dividing wier. The pool will then serve both purposes, enjoying a swim in naturally cleansed and disinfected water, an environment for water plants which will be a visual feature and the absolute abolition of any form of "chemical" treatment considered normal for Australian pools.

This "Natural" form of swimming pools has been around in both Private and Public swimming pools in Europe, especially England, Germany and Greece for 20 to 30 years. It is well accepted and documented and there are qualified commercial contractors here in Oz that provide a full design and install service.
Now, as far as I'm concerned, this is environmental integration at it's best! I can swim with the Fishes. The planted area can be used to "Grow Out" larger fish without the need to plumb to additional Grow Beds etc, maintains the origional purpose of building a Pool in the first place, lets you have chemical free water (it's classed as Potable!!) The plants provide them with natural cover from predatory birds etc and it is easy to cover net (semi-submerged) an area of 4m x 3.25m for jumpers and the like.

I know there are going to be detractors out there who will say you will get the silent "pee" in swimming pool, the eColi will thrive etc. etc.
Bull ****!! This is exactly what happens to water in every stream, river or lake anywhere and don't tell me you have never had a dip in a brown water dam! let alone a crisp, clear stream. Have a look a the creek water at Frazer Island, the cleanest and clearest in the world!! Why . . . because it uses a natural sand/gravel filtaration and water plants for disinfection. They bottle it for Christ's sake, and sell it as natural spring water!! without any other treatment and it's sold to those precious dearies who don't know any better. The exact ones who still think milk comes from a bottle in a shop!

As I said, radical, but this is what I'm doing.
Hope I can inspire you to something similar (by the way, local council approved the pool on the building application. They didn't ask about the filtration, silly buggers). I'l help you with the design if you wish, after you do a bit of Google research on "Natural Swimming Pools"

Cheers IanK.