Backyard Aquaponics
A place to discuss aquaponics

I agree with bunson. +1

I've been watching the odd vid from these guys and I've been getting increasingly nervous about the validity of their information.

I now know not to pay much heed to anything they say. The DTBA CHOP 2 system has got so many problems and only a few very small (some would say insignificant) supposed advantages.

The whole video seems to be constructing a missive teetering straw man that they are apparently cutting down to size with there design. For example when did an overflow drain become a complicated addition?

I've always had a concern about vertical growing systems because their inherent high static head has always seemed inefficient to me. However, I've also thought that maybe there were other efficiency or productivity gains/savings of which I was unaware, so each to their own.

The inefficiencies of a high static head of a vertical growing system shrink into a relatively minor problem compared to the inefficiencies of the DTBA CHOP 2 design.

Last time this came up I didn't take the time to do the maths to work out how bad it actually was but I think I might this time. I think it involves some integration though so its more than a 5 minute whim.

Simple answer: DTBA CHOP 2 design requires the tank be turned over much more than once per hour to achieve the same level of water processing or filtration as a CHIFT PIST (AAGD) design.

Thanks bunson for your input, no I don’t see myself adding anything to my system that would hurt my fish, but the logic off his ideas far outweigh his excuses for adding anything that could be harmful to the fish, we are going to get real hot weather soon here in the west, being able to adjust water flows and other changes could be beneficial to the newbie! Like me, as high temps will increase PH and lower oxygen in the system, being able to adjust flow rates at will could be beneficial, yes you can change a gravity feed rate system but you will need to change your pipes eventually, but with the split flow system, all you need to do is extend the pipes to the new beds? I already have a pressure runoff valve back to the sump tank, which will go eventually to my DWC system, above the sump tank?

You see all things are not just black and white? Forward planning is the reason for me setting up my system the way I have, but I am really good with drawn plans, as I designed this house and where it was located the north/ south and the drive through double carport, yes life is supposed to be easy! You just have to think ahead off what you really want! I live the perfect life!

Happily, my water temp today was 28C.


Temperature wont raise or lower pH. The problems arise with the system solution of TAN, pH and temperature. There's been lots written about it already, here's another one : http://www.aces.edu/dept/fisheries/education/ras/publications/water_quality/Ammonia%20in%20Fish%20Ponds%20463fs.pdf)

Dissolved oxygen is not lowered at high temperatures, at higher temperatures the amount of oxygen which can be dissolved in water reduces.

"The amount of oxygen that dissolves in water can vary in daily and seasonal patterns, and decreases with higher temperature, salinity, and elevation. The maximum solubility of oxygen in water at 1 atm pressure (standard air pressure at sea level) ranges from about 15 mg/L at 0ºC to 8 mg/L at 30ºC—that is, ice-cold water can hold twice as much dissolved oxygen as warm water (Wetzel 2001)." http://www.ramp-alberta.org/river/water+sediment+quality/chemical/temperature+and+dissolved+oxygen.aspx is one source.

It wont matter how much flow or how many airstones you use, if the water is too hot and the fish stock species too fragile and stocked too densely, you'll kill fish.


The need to change flow rates is rare, especially for "newbies." The often-quoted rule-of-thumb of turning over the volume of the water once per hour exists just about all year, regardless of the weather. Whether or not that flow has to pass through every component is a different discussion, but if you did like espoused in the video and pumped water only from to and from the FT/ST, you'd soon have a pile of dead fish and filthy water, as there's no filtering, bio or physical.

If you explicitly monitor feed loads and all of the other parameters required to do all the computations you can adjust the required flow rates through the filtration, but anyone sailing that close to the bleeding edge is asking for trouble!


Don't confuse "pressure" with "flow". Although a relationship exists, they aren't the same.

Sorry Stuart, but you are completely wrong! According to the information I have received on other websites,
But its nice too see you never change as to objecting to no matter what I say?

Have you sort help in anyway?

Seriously you do need help!

My system right now is basically what Nate showed in the video, except I don't have a valve on the fish loop. The downside of my system is that I am getting less flow overall because the single pump has to pump up to top of the vertical planting height before it is split. With the same pump only having to pump to the FT water level I would have way more flow than now. Whether to have fish poop go to the sump is optional and separate than the idea of splitting the flow to a plant loop and/or fish loop. My FT goes to RFF then media bed then sump and it is still split flow as shown on the white board.

The only reason I used a valve to split the flow was to avoid buying another pump that could go up to about six feet of head, and because I actually had too much flow from this pump to feed just the FT. Ideally I would have two pumps in the sump, which serves the exact same purposes in the video - choosing whether and how much to flow to the FT or plant loop.

This answer isn't for Blizzard because I'm pretty sure we can all assume he isn't listening but for any other peoples who may come across this thread.

SIMPLE ANSWER
Why pump dirty water from your FT back into your FT.

Not so simple answer.

I could go into the maths but its complicated. In fact its beyond my skills but after giving myself a headache trying to solve it using calculus I used a brute force approach in excel.

If you have:
1 IBC as a FT;
GBs that take 1000L to fill with water (ie 2000L of gravel assuming 50% void fraction);
sump which is an IBC.

Assume a pumping rate of 1000L/hr.

If you were to add die (simulating TAN) it takes forever for the die to become evenly distributed throughout the system (11 hours). After 2.5 hours the relative concentrations are 2.3 in FT, 1 in GB and 1.6 in the sump.

In a system based on similar components arranged CHIFT PIST it takes about 2.5 hours to achieve even distribution through out the system.

To get the DTBA CHOP 2 configuration to mix the die as effectively requires that the water turn over rate be increased 3.25 times. This is way more than I thought but really shows the problem of inefficient mixing.

If you have a return from the pump back to the sump then the mixing gets worse. I haven't run the model but I expect it to be A LOT WORSE.

When you post Blizzard I feel a bit like a moth to a flame.

I may be completely wrong but you won't show me to be wrong by just telling me so. Now my intentions in replying to your posts are not to belittle you in fact at this point it really isn't to engage with you at all, although having said that this post obviously is. Rather I don't want to see comments you are making stand unchallenged so that someone coming along later is miss led.

So you say I am wrong, ok fine. Was I wrong when I said that adding an over flow drain was not complicated?

Was I wrong when I said that vertical systems have a higher static head than horiztonal systems?

Was I wrong when I said mixing dirty FT water with the water in the sump to be pumped directly back into the FT was inefficient?

The idea of this forum is to learn and explore. If your understanding of these concepts is superior to mine then demonstrate it. If you do I will be grateful for the education and I will forgive you for the obnoxious way you have treated me when all I have been offering is my sincere help. In your opinion that help is misguided but you have no way of judging its sincerity.

that’s good for you Dave, I hope you have lots off susses with your system honestly,

As I have had nothing but negative feedback from one person in particular no mater what I say?

Aquaponics to me has become a hassle in my life I don’t really need? The aquaponics is fine, its just the idiot that follows me?

Expert? I think not, just a drip under pressure!

Your walking a fine line Blizzard. Personal attacks or name calling will not be tolerated.

Stuart! I am new here that’s true, but you have done nothing but add negative post too no mater what I say? This is over one month off me posting?

1 you don’t like filters,

2 you don’t like split chift

3 you don’t like me?

This is all fine by me but there are others that are interested in what I am doing, and have used simular ideas to me! Its fine for you to sit back and tell us all how to do this and that to most people on here? But I wont be apart off that ever! I will do as I want given the best information I have, as I have not received any positive information on this page as to how to make my system better?

I am adapting my system every week to be better than its original state, everything is working fine, I did it all by myself,

You come across as the person that knows everything? But in reality you only know what you have done so far? Step outside that little square for a minute and think back to when you were new to this,

i don't think he comes across as "not liking you" blizzard..
is it that hard for you to take criticism? obviously it is, as you cannot respond to the facts that Stuart has provided you,, it sounds like you aren't here to "learn" but to spread your own gospel.. i've met lots of people that can't admit mistakes/failures, and you're right up there

I decided to watch the video. Nate had some very valid points other then the complex overflow comment that installation isn't rocket science. Stuart I agree with you that recirculating foul water is disasterous to fish health but you got to understand that no where in his video did he say it is unfiltered water. the fish tank loop can simply overflow into a series of mechanical and biological filtration before it reenters the sump. in that way the plants loop are only for growth and not mineralization. I'm not sure if he meant to say this.. but if I had to improve that design of CHOP I will include these additions and it will be a great efficient design. what you all think..?

And Blizzard what Charlie says is correct. we are here to discuss and debate all that is aquaponics and that alone. leave it to Jerry Springger and MTv to discuss personal feelings.

If you believe you have a valid point no all the times a direct approach is best especially how you got sometime to prove your skills. so what I suggest if to limit the speaking and just let your system speaks for themselves. the Heads of this forum has lots of experience under their belt so respect is due to those that earned it. Practicality beats intelligence anyday in the real world.... but I didn't say Practicality is always Right.. if you understand my drift