A Community and Forum For Aquaponic Gardeners

Is an enclosed system harder to manage?

My early thoughts in system design all revolved around having a system in a tunnel or greenhouse. I'm in a temperate region, with a temperature range of 40 degrees celcius (104 F) in summer to 0 degrees Celcius (32 F) in winter. The winters made me want to have an enclosed system purely for heating costs in winter. What I have found in my micro system though, is that the management of an open system appears to be easier than a closed one. I have far less mildew issues, and I do not have serious bug infestations yet, months after opening my system up. I obviously get the big fly-in and hop in problems now (I can always add shade netting) but no aphid, white fly or other small pest outbreaks. Previously, I had to hand pollinate because we cannot buy pollinators in South Africa.

This has made me ponder my future commercial aspirations. The original design was all bio-secure with double doors and what not to keep the system isolated, but now I am thinking: Is it all worth it? I have at least 6 praying mantis that has occupied the area, and my biggest pest control issue is still ants, which got in before in any case. Can some people operating open and closed systems give some feedback here as to their system management concerns and routines, as well as their thoughts on the matter.

0 members like this

Replies to This Discussion

Permalink Reply by Sylvia Bernstein on February 25, 2011 at 6:31am

Hi Kobus. I've done both. Had systems, both hydro and aquaponics, in our greenhouse for years now, and outside the past 2 summers. I completely agree. Oddly the only time I've had powdery mildew on cucumber was the first summer...but I was still learning the ropes so something else might have been causing it. Bugs and fungus are the biggest issue in an enclosure. Non-existent (mostly) outdoors.

The problem I have outdoors is overheating the fish tank. We have very intense sun because we are at high altitude (about 5500 ft above sea level) and if my plants are in the sun and the fish tank under it the tank water can get to 98F. Had a big problem with oxygen last summer. I'll set up an AquaBundance system on our deck again this summer, but this time I"m going to have the fish tank against the wall of the house in the shade and the plants on the other side of the deck in the sun and pump the water between them. We'll see how that goes...

Permalink Reply by Kobus Jooste on February 25, 2011 at 6:48am

Do you have some nice deep soil under that deck? I would love to experiment with a simple coil of irrigation pipe buried underground. The soil temp a few inches down is much lower than atmospheric temps, and my thinking is that sending a stream of water through a long section of underground pipe should be a good cooling system in summer.

Sylvia Bernstein said:

Hi Kobus. I've done both. Had systems, both hydro and aquaponics, in our greenhouse for years now, and outside the past 2 summers. I completely agree. Oddly the only time I've had powdery mildew on cucumber was the first summer...but I was still learning the ropes so something else might have been causing it. Bugs and fungus are the biggest issue in an enclosure. Non-existent (mostly) outdoors.

The problem I have outdoors is overheating the fish tank. We have very intense sun because we are at high altitude (about 5500 ft above sea level) and if my plants are in the sun and the fish tank under it the tank water can get to 98F. Had a big problem with oxygen last summer. I'll set up an AquaBundance system on our deck again this summer, but this time I"m going to have the fish tank against the wall of the house in the shade and the plants on the other side of the deck in the sun and pump the water between them. We'll see how that goes...

Permalink Reply by Sylvia Bernstein on February 25, 2011 at 6:53am

Nope...we have a sloped lot with a walk out basement and the deck is above it. All facing south. Your concept is a good one, though, and should work in the right scenario.

Permalink Reply by TCLynx on February 25, 2011 at 7:31am

In my minimal experience between greenhouse and outdoors is that there are fewer bug and plant disease problems out in the open. Or maybe it's just that the natural predators and breezes help control the problems enough that we don't have to worry about it.

I still get some problems here (our climate is very conducive to powdery mildew) and some pests like ants farming the aphids still happen but for the most part it isn't stopping production so I'm not worrying much over it for a backyard system.

It seems most of the issues are in the big system where the pH tends to be too high and iron lock out is a regular problem so the weaker plants get attacked more. The other system running a lower pH seems to be doing better so far this year. Except for the water cress which has gone crazy in the high pH system.

I had some frost blanket covering my raft tank for a while (mainly to keep the leaves out) but the aphids and scale insects totally attacked everything under it so now I'm leaving it off.