What kind of soap can I put in it?
Thin to medium liquid soap is the safe answer. Solvac pairs a 500 millilitre reservoir, 17 ounces, with a small electric pump, and pumps of this type work best with soap that pours freely. Ordinary liquid hand soap works well, and washing-up liquid can work at the kitchen sink. Anything very thick, such as a heavy moisturising cream wash, can strain the pump and gum up the nozzle, so thin it with warm water until it pours easily. It dispenses liquid rather than foam, so foaming hand wash made for an air-mixing pump is the wrong fit.
It gives too much or too little soap. How do I change the dose?
Turn the switch. Solvac controls the amount through the power switch, so the same control that turns the unit on and off also sets how much comes out, and it works as a simple dial with a definite off position. One owner finds the lowest setting right for a standard hand wash. After changing the setting, trigger the sensor a few times over the sink so you can see the new amount before you rely on it.
How do I mount it, and will the wall hold it when full?
Plan for real weight. The unit weighs 1.1 pounds and a full reservoir of soap adds noticeably more, so the fixing carries a load that gets nudged every time a hand reaches under it. On smooth sealed tile or glass an adhesive mount can work, but only on a properly cleaned and degreased surface, left to cure fully before you add soap, because bathroom humidity is what defeats tape. On plasterboard, paint or textured surfaces, screws are the dependable choice. It also stands perfectly well on a counter if you would rather not drill anything.
What batteries does it take, and how long do they last?
Four AA batteries, and Solvac places the compartment on the back of the unit specifically to keep it away from moisture. That is a sensible piece of design for something that lives beside a sink. Battery life is a genuine strength; Solvac says a set lasts a year, and an owner who kept track found it did. The cover is held with a screw, so keep a small screwdriver handy when it is time to change them.
What tends to go wrong over time?
Durability is the one clearly negative theme, and outcomes vary widely: one owner reports six years of use several times a day, while another had one unit stop after about two years and a replacement's pump stop after about three. Two things account for many failures in this category. The first is a blocked nozzle, because soap left standing dries in the outlet, and the fix is to run warm water through the reservoir now and then rather than waiting for a full clog. The second is moisture reaching the electronics, which the rear battery placement reduces but cannot eliminate if you mount it inside a shower splash zone.
Is the large reservoir worth the space it takes up?
That depends entirely on where it goes. At 500 millilitres it holds far more than a typical pump bottle, and an owner says it takes almost a whole refill of hand soap, which is the whole point at a busy kitchen sink or in a family bathroom where refilling is the chore people resent. The transparent body lets you see the level without opening anything, which is handier than it sounds. In a small powder room it is simply a lot of dispenser, and value for money reads as mixed partly for that reason: the capacity, adjustable dose and touchless operation earn their keep in a high-traffic spot and feel excessive in a quiet one.
