If your whole family can use it, and the strength is different, and there are old people and children playing, then buy an adjustable resistance.
In fact, infinite resistance is not adjustable and can meet the needs of most people. After all, power is your own control. If you want more resistance, add more water to the water tank, and then paddle at a higher frequency to ensure that you sweat within five minutes. If you don't want that much resistance, it's enough to paddle at low frequency and do aerobic exercise slowly.
Adjustable is more designed for the convenience of family.
There are two main designs of adjustable water tanks in the market, one is a layered water tank, and the other is a blade control opening and closing.
The former is to adjust the resistance by controlling the amount of water driven by blades, such as Wow Coffee's patented water tank.
The principle is that the more water the blade drives, the greater the resistance naturally. The design principle is quite scientific, but the disadvantage of implementation is that the flow of water mainly depends on gravity, which leads to slow drainage.
The design point of the latter is paddle. In fact, strictly speaking, it should be called adjustable paddle, such as Mo's rowing machine.
It has a design on the transmission shaft to make the blades fully open or close. Its principle is to adjust the resistance through the contact area between the blade and water. It is also scientific. Compared with the former, the advantage is that resistance adjustment is time-consuming.
The above two adjustable rowing machines can be selected according to your own preferences.