Backyard Aquaponics
A place to discuss aquaponics

The endoscope should work well but if it doesn't, you could also use a translucent or transparent container and just keep it wrapped most of the time. Looking from the top it's sometimes more difficult to tell depth/thickness of the sediment.

Bioaqua, perhaps you should actually read other peoples posts/threads.. instead of just shooting from your defensive hip...

Almost all of my initial systems, and all my client systems...going back 10 years...have been based on timed F&D

My more recent systems over the last year or two... have been based on constant flood...

But I'm reverting to timed flood and drain... (with indexing valves... which I used well before you even found out about AP)

As I have found that there's no significant benefit to running constant flood.. some cons... and because I can configure my system more efficiently in other ways...

Both timed F&D.. and the use of indexing valves were around for a long time.. before you "discovered" them... and built your system Bioaqua... yet you seem to be claiming some sort of "innovation"...

Yes I questioned your design...


As to why you were using timed F&D.. with a Chift Pist/Chop2 design.. with siphons...

I didn't post as to why you would use Chop2... or media beds (timed or otherwise)... in a commercial operation at all...

My views on both.. regarding commercial system design... have been posted many times before...



Well that certainly wouldn't be any great revelation...

And hey Bioaqua... you're system seems to be working fine for you... as does the implementation of the guru you allude to...


Would I build a commercial system based on either concept... not in your life...

I'd never even consider media beds.. or Chop2.. in a commercial design..


Would I build a hobby farm system based on either concept... probably not... there are better ways...

But it can be made to work within limitations... but not beyond...


Would I build a backyard system based on either concept... why not.... and indeed I have... going back 10 years...

Although I wouldn't have a bar of Chop2...

Other than re-inventing an often re-invented wheel Bioaqua... sorry, but you're really not posting anything that startling innovative.. at all...

But as I said... hey if it's working for you... great...

I just found this thread.... can't believe I've been missing all the action!

I'm seeing a large difference between my Constand Flow Flood and Drain (CFwFnD) bed and my Constant Flow Constant Flood (CFwCFd) Bed.

First off the rhubarb.



And for a direct comparison:

The small one at the top is the largest leaf I could find off the CFwCFd plants which was easy because I can see them all. The other is a large leaf but I couldn't see very very to find the largest because the growth is so wild.

Second is the corn.





No the corn in the CFwCFd bed was planted a week or so after the CFwFnD bed but the gap between them just seems to be getting wider and wider rather than just a week behind.

Hey Stu, I can imagine (kinda) what a "Constant Flow Constant Flood" is but I don't understand "Constand(sic) Flow Flood and Drain" could be?

Some enlightenment would be much appreciated. Haven't see you in a while, you been laying low?

Regards, Martin.

Yeah, the explanation was more confusing than the original statement . Everyone has to say it their own way but I do think he means constant flow with siphons.

I think it's too close to "constant flood" for me to be comfortable.

It must be just me because its seems perfectly clear.

The reason I don't say constant flow with siphons is because I'm talking about how the water moves through the bed and how the bed is operated to grow plants not how the bed is emptied.

CFwFnD applies to siphon operated beds but it also applies to flout, valve, pump or some other way of emptying the bed.

I just feel that the how the bed is filled needs to be characterised as well as how the level is controlled.

The actual mechanism that is used to empty the bed is less important to me.

Because we always need more acronyms, my GBs operate on the P2HTGD2LTFnD system. Pump to high tide, graviatational drain to low tide flood and drain. The ST operates on the P2LTGF2HTFnD system - Pump 2 low tide, gravitational fill to high tide.

The FT has a much smaller tidal range, using the EGH&LT system- Earth Gravitational high and low tide, with no gravitational assistance from moon or sun

I'm not having a go at you Stuart, just the whole crazy use of acronyms in general, everywhere!

Mine's a CFCFwALAIC (Constant Flow Continuous Flood with Airlift Assisted Internal Circulation)

Well you totally forgot to put this part in.

It is no doubt filled through a pipe connected to a pump guys. :phew:


Anyways, thats a nice difference, well not nice, im a fan of CF, F&D sucks.
hope all is well stu.

Now that I've created a thread for everyone to have a laugh at my expense (including me) back to the plants.

I've been very interested in beds that were constantly flooded but I've always suspected that they may run into trouble. What I think is the problem is that my bed is too large to be run as a constant flood bed. If I am right and it is a lack of oxygen that is the problem you then it is quite likely that you wouldn't see this problem in a small bed.

My bed is so long that I believe the water is getting depleted of oxygen after the first 2m or so. It stands to reason that if DWC needs airstones every so often then why wouldn't a constantly flooded bed need the same?

I remember questioning somebody with a commercial system about that, I can't remember who. But they said DWC can go for quite a long length without air stones, as long as the oxygen levels are at saturation.

See what it says when your fancy DO meter arrives.