Holding Tank chips

[carone]

8 year old plastic holding tank began jamming my 8 yo macerator for the first time ever. Cleaning out the 33gal tank I find hard flat chips looking like guitar picks layered on the bottom centimeter of the tank. These chips are found in my jammed rotor requiring manual removal.

Putting my fingers to the bottom of my tank it feels like putting your hand into an inch of ten cent coins. They are dark brown and the larger ones can be fractured between your fingers. The smaller pieces can’ be broken. The chips are about 2 mm thick.

What are the chips? How to prevent their formation?

[peghall]

Those "chips" are urine crystals aka "struvites" most commonly found in tanks on boats with toilets designed to use pressurized fresh water. They're the result of using too little flush water--common among VacuFlush toilet owners--and failure to thoroughly rinse out the tank 2-3 x season.

There are a number of products that claim to dissolve struvites...I'll let others offer their recommendations.

--Peggie