Backyard Aquaponics
A place to discuss aquaponics

Hey all. Just getting started. I designed it around a single pump and the bell valve autosiphons off the Affnan videos on youtube. Pond is 4'x8'x26". I have the option of running this continuously (~7.5min fill, 50sec drain) or with a timer for spurts of flood and drain (6a,12pm,2pm,6pm 15minutes on?). I haven't got that far yet.

Put some 40% shade cloth over the beds... the "front" faces east so morning sun shouldnt be too bad, but we have some intense summer here in central Texas so it seemed like a necessary thing. The cylinder on the side is a prefilter to try and remove the heavy solids before it hits the grow beds. Plus I can drain the tank with the ball valve at the bottom. It is taken in principle and design from this design:

The prefilter looks like this on the inside:

The lower half of the beds are hydroton (expanded clay balls) and I put a couple of bags of mountain granite on each bed to keep the hydroton from floating during the flood. In the middle is the bell siphon (spill over is 2" OD and the center tube is 1/2" OD) also [url http://www.youtube.com/watch?v=vXaPn6SjvxU ]Affnan's design[/url]

At the current flow rate out of each grow bed spigot, the fill rate is ~6-8 minutes

The dump is about 50sec or so.

So far Ive got a few 4" Koi and a mexicana lily, and running the thing continuously to check things out and establish the water and beds. I did water tests for the first time this evening and have a few things to remedy tomorrow, mostly pH (9+!) and we'll start from there. Plan on some lettuce, broccoli, chili peppers, cauliflower, artichoke and herbs. Gotta find some cats.....

Very neat looking system

That looks great!

Could there possibly be something in the granite that's pushing
up the PH?

If you have some left over maybe soak it in some water and them test
the the water before and after to see.

Please keep the posts and photos coming.

Great compact system and welcome to the forum, as Decal says, keep the posts coming.

The municipal water here is 9.8 pH nearly year round. It is ridiculously high, and I was under the impression that parts of Minnesota and Texas are noted for having very high pH water. We have lots of limestone here.

The granite is supposed to be as inert as it gets, and I did wash it.

I kind of think you want the solids in the grow beds. The gravel should stop it from going back into the pond. Some people put worms in the GBs to help break down the solids.

You should probably read the last few pages of Dejavoodoo's thread. He's in TX and municipal water killed his fish.

Yep, you only need a pre-filter if you're feeding NFT trays, or floating rafts...

pH 9.8... ... jezz... you wouldn't need soap to wash your clothes... then again, it would not only dissolve the stains away.... but the clothes as well...

You're going to find it really difficult to cycle... grow fish and/or plants...

You need to consider using rainwater.... or pre-treating your water to adjust the pH....

our well water is just a bit lower on the pH. 8-8.4 usually but I was able to use some pool acid to pre-treat some water down to a pH of 7.6 before cycling up the system.

Nice compact little system...

2 week update:

I started everything from seedlings in rockwool except for the radishes. They came from the thinning of the dirt bed patch. I didnt use the moon cycle (Aside: Is that a legit improvement in growth???). I have a whole other batch of seedlings I started two days ago. I also did not pay attention to the moon, but looks like I planted on the new moon.

In order to avoid root rot, Ive been running the pump 24/7 to try and turn the water over 4x per day (500gal @ 83GPH [4' head]; 1900L @ 5.2Lpm [1.2m head]) so that I get good aeration for the GB and the fish. Every 6-8min it drains one of the beds. I also setup a simple plastic funnel aeration cone. I took an 8" funnel with a 1" lip and drilled holes in the lip. I stuck a 1/2" PVC pipe up through the center and ran a hose from a really basic fish air pump up underneath it. I think it is helping. I got a couple of big air stones, now all I need to get a bigger air pump

So this was my water reading from yesterday morning:
{ pH | NH3 | NO2 | NO3 | PO4 | KH }
{ 7.1 | 0.25 | 0.25 | 10.0 | 10.0 | 3° }

The water seemed pretty good, so I started thinking about my catfish needs; my understanding is that you want 5lbs of harvested fish for every 25gal of GB (~2.4kg fish per 100L GB?). My GBs, completely filled would be 55gal [200L], but they are only filled 2/3 full, and that is on the shallow end of the barrel.. lets say Im at half capacity so that Im holding 25gals of media per GB. If so, I can grow out 20 catfish to 1 lbs [2.2kg] with the GB space I have.

Next step was to either find local people that had some fish, or I had to go around and collect the places around my area that had catfish fingerlings; I figured Id make a Google map for Texas fisheries/hatcheries: http://tinyurl.com/29p9v33. I went out to San Marcos and met up with guy that does freshwater sport fish lake management; picked up 25 channel cats [6"] for $15. Got a few extra for Murphy's contribution to the project.



So... Ive got a bag of Laguna All Season Koi and Goldfish (large size).. I feed them, and the cats will get to the surface to eat. Question: should I be feeding them catfish food, or is this stuff okay for the time being? What SHOULD I be feeding them? Im working on a BSF bucket to utilize 40lbs of spent grain from monthly beer brewing activities; my reading has indicated that BSF grubs are too fatty to feed to them all the time....

I'd say call up local feed stores and see who carry's purina mills products. Se if they can have a bag of Aquamax 4000 dense culture feed put on the next truck for you and what they charge for it. That is what I feed to the catfish and it would probably work for blue gill as well and many people feed it to tilapia also. Most "catfish" feeds I've seen or the "pond diet" that tractor supply sells is actually meant for fish in natural ponds and might not be complete nutrition.

There may be other good feeds out there, I just don't know them.

BSF are great but they should not be the sole feed.

I have bug zappers hanging over my fish tanks as well.



On your calculations of grow bed volume. I'm a bit worried. If those are 50-55 gallon barrels, then a single grow bed would hold about 25 gallons if full and yours are only half full. For this first season you probably only want to get up to the recommended stocking level of about 1 fish per 7 gallons of grow bed media. I think I would push for you to top up those barrels with more media before your fish get too big. Also, catfish can easily get much bigger than 1 lb. We rarely harvest smaller than 3 lb anymore.

Looking good though, keep up the good work!!!!

Bad math.. COMPLETELY filled, each GB would be 27.5gal [100L], but in reality, Ive got about 15gal of media per each GB.. total of 60gal [225L] of media. So I have 25 cats and 3 Koi, 60lbs GB * 5lbs/25gal GB = 12 lbs @ harvest. By 28 fish.. does that mean that by the time they are 0.4lbs/per fish, Ive over burdened the system?

Ive got two more 55gal barrels, but Ive got to build a stand and still plumb then get some media.. lots of limestone in the pebbles you get around here...

Heya Mars

I responded to your email

How did you get your pH down to 7.1? Is it stable there? Is your KH stable at 3?

I used Seachem acid buffer .. sodium bisulfate I believe. I carbon filtered about 350gallons of my FT initially. pH was 9+, which is typical here. I think I added 50g to 500gal. The KH was only 4 or 5° before I added it.

As far as I can tell, it seems stable. I was wary of the high limestone issue from the get go regarding media choices. Its funny, I wanted to do this project for some time, but found the media, particularly hydroton, to be cost prohibitive. I recently had a friend show me a busted MJ grow operation where apparently the authorities threw the hydroton out on the ground... it had been sitting there for several months and I was able to salvage about 200L. Therein was the impetus to start this whole thing in earnest. So.. the hydroton and the mountain granite dont seem to buffer any of the alkalinity. Since I overstocked, I need to get more GB and hence more media, but havent found much gravel type that doesnt have lots of limestone.. I may just have to go pick up another 200L of hydroton.

Never saw the email..

Sodium bisulfate is normally used to reduce Ph.

If it is sodium bisulfate be careful, I was using it at one point until I had an algae bloom. Did a phosphate test and it was off the scale.