Greenhouse temp in winter

[bsfman]

Hii,
I live in the south of Iraq , I have about 300 tilapia (small ones ) , The winter is relatively cold over here ( may be the temp will as low as 5 degree centigrade , may be lower ) , I am thinking of building a home made greenhouse , I am asking about the temp this greenhouse will provide , and how efficient it will be , I mean if the temp is example 5 degree Centigrade , what will be the average temp inside the green house .
Best

I use a plastic uninsulated greenhouse tent in south Florida during wintertime. Though our winter days average a high in January of 75F (24C) we do occasioinally have nights that drop into the 40's and rarely into the 30's. On sunny days, I had daytime temps inside the greenhouse of 120F to 130F. The thermal mass of my fish tank held the water temp in the low to mid 60's even during the coldest nights and the rare frosts were never an issue. I had to artificially heat my outdoor fish tanks on the coldest nights, but the tilapia thrived inside the greenhouse without any outside source of heating.

I would assume Iraq has LOTS of sunny winter days so a greenhouse might be just the thing to keep your tilapia happy and thriving, Asaad!