Hey friend. I had the same question. PLEASE CHECK THIS OUT!
Blumat Tropt from sustainable village. Sold in USA and Eu. I was skeptical but I'm telling you I had it over 3 weeks now and I have not watered my plants by hand once at all since ! It's amazing, follow the directions and 50 you tube videos and your golden.
No power cords, gravity drip only. By a 13 gal reservoir and put it on a tall stool or something a few feet above your pots. You can use coco or soil. Couple example photos.
I run 4 (3 gallon coco) all on one reservoir and I can get 5-6 days on 7 gallons. If you hand water the day you leave. You may save a few gallons.
Read up on it. It takes a couple weeks to dial in. Small adjustments here and there to learn. Iv had 2-3 situations in the first couple weeks where 1 pot ran away aka water kept dripping beyond holding capacity and flooded the pot. No big deal just adjust the individual watering carrot that u put in the soil and make sure the lines have no air bubbles or debree. I installed fuel filters and fixed alot of issues related to that. I'm telling you. 3+ weeks I have no watered once. They use less water than normal and no run off needed except occasionally by hand your choice. Also I'm using the light nutrient feed chart available for my brand. General hydroponics Flora series. I bought gallon jugs this year and if use this system on my others as well I will literally have nutrients beyond expiration. You need so little since no run off. They grow 2-3x faster than regular soil hand watered IMO. Almost as fast as Dwc, hydro.. if not the same. It's amazing. Good luck, I was afraid of anything hooked up to a hose or timer. That shit fails. So can a blumat but at least you only have a reservoir that can run out eventually. (They use 5 gallon buckets for reservoirs in the videos but I like 13 gal for a few pots. Less refills.
I'm so glad I got this for vacationing. This weekend is first trip away fingers crossed but it's been working well.