Backyard Aquaponics
A place to discuss aquaponics

Ok, thanks guys.

I dont think we need to worry too much about surface area of the media becuase even the UVI sytem with no gravel had enough surface area for nitrification. Surface area is a concern in AQ becuase they are trying to minimise the size of bio filters.

The surface area that is important for a balanced system is the growing area. The volume of the gbs is important so that there is enough space to retain/store the solids and provide a habitat for the beasties that eat them.

A quick note to everyone who might be using Wilsons design calculator. I received an email from him yesterday saying that there was a slight error in one area of his calculator. His comments were as follows:



The new version is available on his website, and from the initial links at the start of this thread.

Thanks Wilson..

Wilson asked me to post up here and let people know he has updated his calculator, so if you use it, you might want to download it again..

Hey there fellas,

I was checking out Willson's calculator and I've been quite surprised by the low flow and GB volume values.
If I put in my system that has 1m3 FT with fish density of 20kg/m3, it gives me 6,8m2 of GB requirement and 34 L of biofilter(i'm assuming that's the deep water culture tank) and a flow rate of 350 litres/h.

I'm not trying to disregard Willson's but I know from experience with my little system that a 350 l/h water flow would definitely kill everything in sight. The solids removal capability would be close to 0 and my FT would look like a thick soup.
I have a 8m2 GB surface and even that get's clogged with fish waste in about a year (carps are dirty yes).

The only way I see this working is with massive areators (preferalby oxygenators) and a really good mechanical filter (drum filter, solids settler...things like that).


This summer I did a stupid mistake and I lost more then half of the really good sized carps. I was left with 8 kg of fish. And the system had no problem in producing the same amount of greens, the Nitrate leves were still maintained at 50mg/l and everything flourished.

According to the UVI system and Wilsons calculator, I could only support 2m2 of greens with that.

Now I've read several experiences from commercial AP growers that even with lower stocking rates the plants were doing fine and that there's a choice in either more fish oriented AP or more plants oriented AP.


I'm working on a commercial size AP as we speak and this calculator kinda rocked my mind and totally contradicts my experiences.

What are your thoughts on this regarding to your experiences?

I've never really tried it.. Perhaps he has a newer version on his site? Personally I don't think that a simple calculator can give the answers most people are after, and if they are after those sort of answers, then they generally have the knowledge to work it out themselves.

I've read a lot of info that he's put on and I now understand from which standpoint is he coming from.

Our DIY hobby systems and his proposed commercial sized systems are from two different worlds. I definitely have gained a lot of useful info from his site. I will check myself on the sizing of the gravel filtration but everything else...i can say just hats off to mr. Lennard!

There are some useful fact sheets available from Wilson's site as well as the Calculator. The Fact Sheets are at Wilson's Fact Sheets and here are The Calculators

I think this topic should be pinned. Great info

This is a great tool! Does it work for ponds instead of fish tanks? I'm currently trying to design a pond aquaponic system in Uganda.

Ooooh this is cool!

Moderators could this be put up somewhere important...like "read this first...before!!!!!!! registration

Bump

It looks like it's the first unlocked post in this section of the forum and the whole section is listed as useful information - seems like it's in a pretty good spot as it is.