I have used the Wall of Water in the past. I haven't done it for awhile because I was planting late. I always thought they were protective on a cool night. And of course, they work best when you have some sun during the day to warm up the water and then it releases the heat at night - supposedly. I did feel they were worthwhile when I wanted to plant out early.

I bought a couple of these.....

weather protection for tomatoes

But I haven't used those much either.

I would think you would be better off with the Wall of Waters then without, if your weather is still cool. It really should be heating up soon!!