I guess when water is at a minimum and the heat is high, you need to do everything you can. Very creative ideas!
I am looking into rain barrels/a rain tank now. The food forest with its 40+ trees/bushes/vines/annual & perennial vegetables is going to take a lot of water, more than we have ever used before. Luckily, except for 1 year out of 27, our well has always been full. However, with more watering we will be using the well pump and the tank that creates the water pressure (forget what you call it) a lot more. Thet means more electricity and the possibility of replacing equipment if they should fail. I'm just starting to research now. My tendency is to go with an opaque black tank of 300-500 gallons to eliminate algae, but then the black will keep the water temperature too hot. I could have it buried, but that adds to the expense. There are insulating jackets that can control the heat, but I am just starting to read about them. I wouldn't need a pump as it will be placed high on the hill above the FF, so it will feed by gravity. As I said, I just started looking into this idea last night.
We have an assortment of rain barrels and tanks. Our first was one my sister made from a recycled pickle barrel (black). It came with us to Texas, and while the water does get somewhat warm, it’s never too hot for watering the plants. We added a second smaller barrel that we made ourselves when we still lived in Virginia. With the rain we got there, they got refilled often, and they met our needs. (Our garden was also very small.) Once we moved to Texas, however, we realized that we needed to catch much larger amounts of water so that we could store and use it for long dry periods. We do still use our black barrel here, though, and it doesn’t get too warm. It doesn’t have a huge amount of sun exposure in its current location, though.
Our current garden tank is 500 gallons and is dark brown. The hose attached to it gets very warm from lying in the sun, and I just the other day burned basil leaves with it before I realized it had heated up during the break I had taken. The water coming from the tank is much cooler, though. We’ve used this particular tank for almost four years, and I don’t think there’s ever been an occasion when we thought that we couldn’t use the water because the temperature was too high.
Our newest and largest tanks are both pale beige but have thicker plastic than our other tanks, and we have not had a problem with them growing algae. I think as long as you find a good quality tank, you can choose the color to match your preferences. I think the brand of our beige ones is Enduraplas, and one of their points of pride is that the plastic is completely opaque to prevent algae growth.
I wouldn’t think burying the tank or any kind of insulation jacket would be necessary in your circumstances. I wonder if those are more for protecting against winter freezes for people who don’t drain their tanks or for some specialty plants that have super-specific needs. I figure if our water remains at an acceptable temperature in Texas, yours ought to in Pennsylvania.
It continues to be hot and dry down here. When I went to refill my ollas this morning, I was surprised to find just how low some of them were. Some were completely empty. This May has been very hot.
On a different note, while I was watering I saw one spot where a red potato was poking out of the soil. I decided that instead of burying it, I’d just grab it and find a few others to make a nice dish of new potatoes to go with our leftover mushroom and onion gravy. My kids just loved mashing the blue (purple) potatoes into the others. It made a lovely lavender, and new potatoes taste so good!