Backyard Aquaponics
A place to discuss aquaponics

Yep, the trial has what I would call a "constant flood"... as you yourself do TCL... as opposed to "continuous flow" as in raft/raceway DWC systems...

And I re-read Murrays post and you're right... what he set up is more modified NFT type of system... similar to what many do when they use stormwater pipes for "nft"....

So hard to compare results from Murray's "trials" to those at BYAP...

Interestingly, and purely by un-intended chance one of the beds in the Holmes-A-Court system... and the two end beds in the Bamarang system... as a result of the fall in the greenhouses.... basically run as constant flood...

And in both systems... are doing just fine....

Mind you... so are the other beds.... but you can see the head start of the constant flood beds in the Bamarang system.... and I think the benefit has been due to the extra water level during some pretty hot days within the greenhouse...

It's a little hard to draw too many conclusions though... as the beds were staggered in their plantings over a week or so... and a lot of the initial seed sown was burnt off not long after germination...

Don't sweat it EB, when you are in business you always end up with some critics. Just keep truckin' along and most of your clients will love you for it.

I thought the point of the thread was quite clear. Test out 3 different styles of BYAP systems as a whole and note the differences in operation. The author of the email you received mistakenly assumed it was a test to determine which was better, auto-siphon, CF, or timed F&D, which it is not.

As a test of the 3 different styled systems it has so far been successful. There have been many interesting differences of note.

System 1: auto-siphon, cycles faster than timed F&D, slower than CF, Plant growth initially not as strong as either the CF or timed F&D systems yet will grow both fennel and rainbow chard well
System 2: CF, cycles the fastest, strong plant growth although still not as strong as timed F&D, Some plants will not grow in it (fennel) and some plants which are prone to heat damage thrive in it (rainbow chard)
System 3: timed F&D, takes the longest time to cycle, strongest plant growth although heat sensitive plants may not do as well during hot weather (rainbow chard)

None of these results show that any one system is "better", each of them has their pros and cons. Maybe a combo system with both CF and timed F&D beds for growing different plants? Or auto-siphons for growing a larger range of plants? Lots of possibilities.

The author of the email also mentioned Murray Hallam's systems. This was not a test of Murray's systems and may not apply to his designs. He would need to do his own tests.

Just my opinions... Really just pointing out what EB stated in the beginning of the thread, if you read it.

It's not an email, this is on a public forum, and from what I can see it's a way having a bit of a dig at me because I'm not flavour of the month in that camp, and a way to create traffic. Cheap and trashy stuff, but it works..



Funny, because from how I interpret what was written it was clearly suggested. "he would not let his horse lose this race - especially not in a public forum". It's created 4 or 5 pages of debate overnight on said forum, so I guess it done it's job. The weird thing is, carrying on the horse racing analogies here. When your focus is "horse racing" in general, when that's your aim, the racing industry and the success of racing, you don't care what horse wins. It's about racing, not individual horses and who wins and loses individual races.. Bigger pictures....

But enough about that, into the data for the last two weeks..



I notice for the last 2 weeks that the ammonia levels have gone up a little in all systems, also at the same time, we have now swapped people who are doing the testing. Matt was running the tests but he's left us to go doing tiling, lots of money in tiling . Carl is now doing the testing and he could perhaps be interpreting the colours a little differently to what Matt was.

Also I see our feed rates were down quite a lot for the last week, this is probably just because feeding has been forgotten, rather than the fish not wanting to eat.

Below are the temp and water usage results.



Early water consumption data wasn't really well measured but for the past 2 weeks we have been using a flow meter , this should give much better accuracy.

Oh I love the tracking of things.

I'm curious about how the changes in pH level might correlate with water top ups, feed levels, or additions of buffer.

Anyway. This kind of reporting is so cool and I thank you so much for doing it.

Yea, different eyes doing the testing. Or heck even the same person doing testing under different lighting can mean for variations in how things are read. (I'll guess that reality comes out some where between 0 and .25 for most of the 0 or .25 readings on the ammonia, the Yellow to green can be so difficult.)

A PH adjustment should fix ammonia which should read zero all the time at this stage of the trial, I also think feed rates should be identical in all 3 systems.

Looks like pH adjustments were made during late January, and first week of Feb Aquastud...

And the ammonia has gone up... although only marginally... and I suspect, as suggested that it's more due to the observation/interpretation of new personel, than anything else...

Feed rates are different for each system because of whether the fish are hungry in each different system. I don't see any sense in either making fish go hungry in some systems, or over feeding other systems when they aren't hungry.

I don't know, there are a million different ways these experiments can be done, we are trying to look at it from the point of view of three different one bed systems owned by three different people running each one differently. Those three different people would feed to their fishes demands.

Were no pH adjustments, I might have to go and check our bore waters pH. This may account for some funny readings.

pH shifting due to extra water top ups would definitely follow, I know it does in mine.

I take your point, but with too many differences between the systems what will the trials actually prove? I think the feed rate is an important issue as it is the only controlled variable that will alter the outcomes.

These trials are a great idea and will probably have an influence on how peoples new and existing systems operate, so I believe the more accurate the results the better for ever one.

To setup a full proper "double blind" scientific study.. as pointed out on another forum... with independantly verified scrutinisation of data results...

Would require 9 identical systems, in an environmentally controlled situation to exclude any external varibles... time, and probably significant funding...

For the purposes and intentions it was set up for... the trials have validity, and I applaud Joel for doing so in the public domain...

To the knockers, naysayers, entrepenaural intentioned, self promoting, recent auqaponic experts whether self proclaimed or supposedly "internationally recognised"...

Put your money where your mouth is... and do it... or obtain the funding and organise the scientific personel.... aquaponics needs more "scientific" study...

People will always find issues with other peoples test....

Even the simple F&D with timer....if we take it to the anal degree, should we test with several systems at 5, 10, 15, 20, 25...etc flood?

CF, F&D, Siphon - 3
Scoria, Expanded Clay, Bluestone - 3
1 pass of FT water every 2 hours, 1 pass of FT water per hour, 2 passes of FT water per hour - 3

Can someone work out how many permutations there are?
Can someone then times by 3 to validate the results?

The test here is trying to peove a simple hypothesis. Cant we leave it at that?

Well its prompted me to try CF after a siphon started playing up, and now half my beds are CF and I am loving it.

And that alone should be justification enough Mantis... it gave you another perspective and another avenue to try...

It really is a storm in a tea cup... and frankly... I don't think it's entirely about the "trial" itself...

I would say it has nothing to do with the trial, so Joel should not be worried.