Not all aquaponics requires a greenhouse. If you live in a sub tropical or tropical climate a greenhouse has some challenges that might be easier to deal with by skipping the greenhouse in some cases.
There is far more to an effective greenhouse environment than simply a plastic cover. In a hot climate a simple plastic cover is an effective way to cook your plants and trap the pests in with them. In a really cold climate a simple plastic cover isn’t enough to keep things flowing through the cold season. Decide carefully if that simple plastic cover is going to be appropriate before you depend on it to make your growing easier. I’ve found for effective greenhouse growing some automation and climate control (even if it is just thermostats that can open/close vents and turn on/off fans) are rather important. Few people have the time/patience to always be on hand to open/close and turn on/off ventilation in a simple greenhouse when it is necessary.
I happen to live in an inland, humid, subtropical climate. We do get freezes and frosts occasionally but most of the year (sometimes within 24 hours of one of those frosts/freezes) it is too hot for a sealed up greenhouse. My first two Aquaponic winters I was trying to run under a simple plastic cover type greenhouse and I found that when it was warm and sunny, the greenhouse tended to get too hot and the cool weather crops suffered but when it got cold at night, it was cold enough that some of the warm weather crops didn’t really like it much either. So there I was during Florida’s best growing season with a bunch of plants that were suffering from spider mites and aphids inside a greenhouse because I was trying to recover some heat to keep tilapia alive through winter. My by third winter I was told I had to take the “greenhouse” down by code enforcement and that actually turned out to be a good thing. That third winter I lost all the tropicals in the system and didn’t try to grow tomatoes through winter but the cool weather crops did wonderful and I had far fewer pests problems in the aquaponic plants year round after that because I had better air flow and beneficial predators to help with pest control.
From now on in my book, greenhouses are for those willing to install something that can support some automated vests, fans and other heating/cooling devices. My schedule and temperament are not appropriate to monitoring greenhouse conditions 24/7 to deal with opening/closing things up and turning on/off fans and the like manually.
I need to build a temporary greenhouse, just for a few days each winter and about a dozen nights. It should come off in the morning, but might end up staying on for a day or two at most if I am out of town. Can I just use any kind if clear plastic, or is something else worth considering ?
If it is just to protect from the occasional frost/freeze….
I might recommend frost blanket instead of doing plastic since if you can’t get the plastic off in the morning and it is sealed up tight and it gets hot and sunny, the plants could really cook. The frost blanket will breath more and still lets some light in so if you don’t get it off right away the plants should still fair well enough.
Also since the frost blanket will let water through you don’t have to worry about a flimsy structure being collapsed by rain and if the cloth touches the leaves on occasion it is fine where as if you cover with plastic you have to make sure the plastic isn’t touching the plants.
Plastic for greenhouses is getting more and more popular these days. I would like to show you why.
Perhaps more popular but I’m still not convinced that a greenhouse is really needed or appropriate in my climate unless you are also going to put the money and ongoing electricity into active heating, ventilation, and air conditioning for it. In which case some form of double layer insulating glazing is probably more appropriate than a single layer plastic film.
Simply making a plastic or glass enclosure is not appropriate year round to a wet sub tropical climate.
If one is going to use a greenhouse, one should spend some extra time researching climate appropriate designs and technology for their specific location AND planned crops. Otherwise a greenhouse could simply cause more problems than it solves.