Backyard Aquaponics
A place to discuss aquaponics

hehehe - one idea is to come along to the next Bris meet and look at a running system, bring "DB" and he can ask all the questions he wants, I think vb is organising it for Jan/Feb - info will be thrown up on a thread when finalised

probably doesn't belong in this chat thread ... but he asked what kinda evaporation we'd be looking at in such a system.
a) how could it possibly be more than in a compact grow bed? same surface area, right?
b) how much water do you actually lose via evaporation?

ohhhh YESSSSS

promise me there'll be lots of others who can answer his questions?!?!?!
(Me, I'm no scientist, just a dreamer!)

Evaporation, there is basically 2 ways:
1) due to heat/sun, this can be minimised by not having fish tanks in direct sunlight or by covering fish tanks and is not an issue (to me anyway) - nutrient rich water in direct sunlight promotes excessive algae growth ( a no-no in AP)

2) due to plant transpiration, this will be slightly higher than with a normal dirt garden mainly due to water permanently and readily being available to the plants and the plants grow more quicker in AP systems, but is negligibly higher.

To put a figure on the amount of evaporation is difficult due to many factors, size of tank, type and amount of plants in grow bed, exposure of outlet to grow bed, positioning of fish tank, etc............

this helps a lot........

In my experience if you can keep the water flood drain (or contiunuos flow entry point) about 1 inch below gravel surface then it cuts down on evaporation HEAPS

Thats it steve 1 inch down I run twice the size aqua beds as dirt garden. Aqua uses 1/4 the water of dirt beds

You 2 referring to the "high tide" level, not actually burying the pipes 25mm deep?

yep

Good - modify my intelligent post previously submitted to include the above L3nny

F&F, you have your pipes below the surface, don't you?

Thats the way i'd do it

yes just burried see pickys

Yep, i rememberd one of the first tips i gave ya was "flood to an inch below"

l3nny, I'm a Computer Solutions Architect (I write the specs that programmers use to code from). Tell DB that I said to just go for it!!!

once a day I flood right to the surface so that the seeds get a drink. Poses no problems with algae cause the top surface dries out soon after.

Yes when i think of it i override the swich for a good drink whitch reminds me havent done it for 2 weeks