Backyard Aquaponics
A place to discuss aquaponics

A friend/neighbor purchased a home 18 months ago that was formerly owned by an Australian couple. As my neighbor had no interest in aquaponics, I moved the greenhouse and AP setup to my home.

The system has not been used for some time, and I am doing my best to get it reassembled and running. At the very least, I would like to get water cycling to begin growing veggies. I hope to take an introductory aquaponics class during the next couple months.

The greenhouse is oriented roughly E-W, with the door on the East. Shade cloth will be required in the Texas sun, though I'm not sure how much filtration will be required. The underlying ground is currently covered with several sheets of cardboard over which I will add crushed granite. It looks like I will need to replace the drain piping (to add a system drain) and drip lines (which no longer have tight connections).

The system consists of:
- a 150 gallon tank equipped with airpump/stone and two pumps - one for providing water to media bed, and another for two drip lines.
- 18 individual grow buckets with various media (one seems to be entirely charcoal?!)
- floating raft bed
- ~8' x 4' media bed
- worm composting basin (I think)




I have several initial questions:

1) regarding the media bed, where should the overflow holes be located in the drain pipe? Mine are pretty close to the base of the bed (maybe 1/2" to 1" above it).

2) the media bed material is granite aggregate, which now has some fines (pieces that have chipped off during transport and installation). While there is a filter around the drain pipe, should I attempt to again wash the rock before connecting the bed to the tank? Does the tube providing water for this bed simply sit on the media at one corner of the bed?

3) it appears that I have two tubes to inject air in to the raft bed. Is it suitable for these to be both located at one end of the bed?



I appreciate any advice as I continue the set-up!

My system is mostly up and running. I started with 40 goldfish, of which about 36 or 37 remain. I added shade cloth and removed some upper panels due to heat over 100 deg. F on some spring days.

The lettuce has grown best, but growth rate of basil and oregano has been frustratingly slow. I bought some tomato Plants at a farmers market. I added one in the Greenhouse and the remaining in the traditional garden. The tomato plant in the greenhouse took off initially, growing faster than those outside, but now the leaves are turning tan, as are the leaves on a bean plant. Squash leaves are beginning to discolor around the edges. The tomato plant is in a container with coconut coir or peat moss, topped with expanded clay. It's on drip irrigation 3x / day. The affected bean plant is in a similar container. The squash are on an hourly flood and drain.

When I tested water last week, nitrate, nitrite, and ammonia were negligible but pH was high (about 8.1). The outside five tomato plants from the farmers market have a similar condition, so it may be unrelated to aquaponics, but I’m a bit nervous that a similar condition seems to be appearing on other greenhouse plants. Any ideas or diagnosis?

Thanks, Will

Overall Greehouse


Tomato Plant


Close-up of tomato leaves

Hiya bridgie and a late welcome to the forum. Sometimes with first posters other forum members can spend time answering q's and the op never returns. Personally I wait for a second post before replying.
So, nice work with the set up, well done.
Generally it takes time for the beds to become the biomass required for growing food hungry plants like tomato's so it's recommended they are only grown once the beds have matured. Having said this there are, of course, exceptions.
Those tomato leaves look spider mite damaged.
The air for the raft should be equally separated in the bed.
Are you running constant flood, flood and drain (siphon) or timed f&d in the gbs?

Thanks, skeggley!

I'll hit the plants with a little insecticidal soap and see if it slows. I've battled an aphid infestation on broccoli already.

The raft definitely needs more air distribution, as I have a single long air stone at one end. I added in a 5 gallon swirl filter for the raft and the pipes, with landscape filter fabric to catch particles. Over the weekend, I replaced the fabric with a home air conditioning filter to see if that improves water quality.

The grow bed pump runs 18-20 minutes per hour, with water coming within 1.5" or so of the top of hydroton, and remaining at that level for a couple minutes before completely draining.

The grow boxes have drip irrigation 3x/day for about an hour each cycle. I need to check moisture levels in the boxes - it may be that the peat moss or coconut coir holds too much water for it to run so often.

Appreciate the response!!

Aha welcome to the world of AP. Insecticidal soap in the water won't be so good for the fish, try not to get too much on the media.
Is the raft constant flow? I used some a/c filter media in some pipe work to clean the water and nearly got caught out with it blocking and redirecting the flow.

Welcome bridgie!

If you need any additional shade cloth and will happen to be in the Dallas area any time soon, I'd be happy to give you plenty for free. I am (at least for now) shutting down my aquaponics systems, and have a LOT of spare shade cloth. it is used, but in good shape.

Shelgeyr - thanks for the offer of shade cloth. Hopefully I'm *covered* at this point - I think what I really need (and soon) will be additional ventilation!

skeggley - I got an email from a local pond installer / nursery today stating they've received lots of calls regarding a problem similar to mine, and attribute it to a cold snap we had last weekend. Greenhouse didn't drop much below 40 to 45 dF, but maybe the rapid temperature change was the cause. I'll keep watching.

The raft and horizontal grow tubes are constant flow. I checked the AC filter today, and build-up doesn't look too significant 5 days in. It's a foot diameter, so I'm hoping to get at least 2 weeks between cleaning/replacement.

My system (and all but one goldfish) made it through the brutal Texas summer. Basil and oregano were productive during the heat. Squash and tomato plants grew, but flowering was minimal and I had no squash and only a couple tomatoes over the summer - probably due to lack of pollination. I also had quite a bit of water evaporation, and I think regular additions of large quantities of water reduce nutrient load.

I'm getting the system ready for fall (which is a great growing time here). Raft bed is filled with water as is the grow tubes. I bought a new air pump to ensure adequate aeration for the raft system, and hooked it up Friday evening. When I went to feed fish on Saturday morning, I found the fish in only 3" of water. The hose from pump had separated from the distributor, and most of water from the tank had leaked out through air hoses. I filled the tank about half way yesterday and will top it today. I relocated the air pump above all beds.

Should I be adding some nutrients in a case like this to temporarily feed plants in this type of situation?

I have been thinking about a reconstruction of my system for a couple reasons:
1) I want a constant level (or nearly constant) in the fish tank. I've had a few scares when I lost most of the system water to leaks or evaporation (a couple times I had to deal with from overseas and instruct someone with no aquaponics knowledge).
2) I have room to add additional grow beds outside the greenhouse, likely for plants needing pollination.
3) I want better thermal mass for the water through summer and winter.
4) I have a 305 gallon tank in place nearby that I originally intended for adding moisture to compost bins. I currently use it to occasionally top off the fish tank with rainwater.

I really would appreciate advice on my redesign plans. Elevations on sketches are approximate but show locations in relation to other features.

Existing system consists of 150 gallon fish tank with about 45 goldfish. The tank has three pumps. One is constant flow to a 5 gallon swirl filter for grow pipes and raft. Another pumps 20 min/hour into the 20 square foot media bed (flood and drain). A third pump sends water through a drip irrigation line for about 4-6 hours/day. This is probably not the most efficient way to run the system.

I am not looking to substantially redesign beds or elevations.

This is an inside view and diagram of current system.



Here is a view of the exterior of greenhouse and adjacent area that could support additional grow beds.


The proposed sump tank (2x volume of fish tank) is at right. I have not checked the top elevation of the tank in relation to the FT, but probably 67% of the sump is below bottom of FT.


I plan to switch to a constant flow pump located within sump that will send water to fish tank and swirl filter. I think I could run a constant flow drip line to the dutch buckets out of the NFT/pipe DWC's, though I am concerned that since they are primarily soil, the roots would remains too wet or they might not drain. If the pipes were truly NFT, I don't think the drip line flow would be a problem.

I am looking at the following basic modified design. Dutch buckets and media bed should drain directly to sump.


I do not know where to locate the flood and drain pump. I would get extra filtering by locating it in the fish tank, though that will cause some fluctuation of water level (but no more than 15-20% of FT volume - probably much less). However, if I add additional grow beds, I think flood and drain pump should be placed in sump.

I believe that I can eliminate one pump in current system, though I will need a heftier pump for the constant flow due to additional head caused by lower elevation of sump.

I would welcome any wisdom or suggestions as I move forward in the next few weeks.

Will

Hey bridgie, personally I'm not a fan of fish tank water going to the sump. It's done sure but the way I see it is that the sump will have fish solids build up in it and this can create issues especially if you are pumping it back to the fish tank without treatment. This system is a chop 2 configuration.

I agree, try to get all the FT water to go to the mechanical filtration before returning to the sump. I didn't plan my system so well and some water from a surface skimmer goes into the sump, I have to clean the sump all the time because of that. Do what you can to simplify your setup. Perhaps convert the flood and drain media bed to Bell siphon so you don't need that second pump? The media bed plays a big part in your mechanical filtration, try to run more FT water through it. Perhaps you can run the raft systems from water coming out of the autosiphon media bed?
Brian

Thank you both for the responses. I didn't like the idea of FT draining to sump (for the same reasons you have mentioned), but information I saw in multiple places pushed me that direction. I have enough maintenance tasks with the greenhouse and home ownership that I don't want routine sump cleaning (and would not want to drain it!).

I will spend some time over the weekend trying to simplify the system, determine how to get the most filtration out of beds and dutch buckets, and researching bell siphons (as it's not clear to me how I could eliminate pumps by using one). Thanks for the advice!

Will

Yes I agree simplify.
So now I've had a proper look how about using your sump as the ft? It has more volume. It's taller.
Can the 305g tank be situated outside with a high water level 300mm or 1' in your language, above the highest gb and use the existing ft as the sump?
Pist chift.

That's a great idea, skeggley! There's actually a concrete pad that is above the top of GB. There are several drawbacks to using existing 305 gallon tank, but I'm thinking I could instead use a 300 gallon rubbermaid stock tank, which I can purchase locally. Constructing a frame around it would allow me to insulate and add a lid to keep rain and critters out. I can find other uses for the 305 gallon tank (like as a top off tank).

I'm still creating an insulated surround for the 300 gal fish tank, and still don't know what I'll use to cover it. Piping is also still underway.

My biggest ongoing problem has been pH. It hovers around 8.0, which I believe to be the cause of poor production. My ammonia, nitrite, and nitrate levels are typically negligible.

I had been slowly adding pH Down on the advice of my local AP store, but realized it would be a constant battle due to regular top offs. My top off water is collected rainwater from a "first flush" system (the water washing a roof during the first few minutes of rain). I decided to test the top off and it's 6.4. As an experiment, I added top off water and several granite rocks from the grow bed (which comprise ~80% of it's volume) to a small plastic dish. Within 24 hours, the dish water had a pH of 7.8. So.... I have a media problem.

I will need to dedicate a day to clean out the grow bed, install a new bell siphon, and refill with hydroton. As I'm still redesigning the system (do we ever stop?), it's not a huge problem, and gives me a chance for improvements... but it's a bummer and time suck.

Will