Urine Unable to get rid of white spots in urine

I would try switching pellets. Oxbow pellets are made with Calcium Carbonate (limestone), which is known to cause calcium deposits in some pigs.
After taking my George off Sweet Meadow (also made with calcium carbonate) his calcium deposits went away. I now feed KMs and haven't had any problems with calcium deposits since.
Small pet Select says that their pellets are made with almost the exact same formula as the leading store brand, so that leads me to believe that they are probably made with calcium carbonate. Of course you could always shoot them an email and ask-- Laurie and Billy are always very nice and helpful.

I've used all three pellets and still had powdery sludge. I limit the pellets to no more than 1/8 to 1/4 cup a day. Offer purified water with no minerals. I rotate purified and distilled water. I no longer feed more than 1 cup of veggies a day. I'm not sure which made a difference but I've seen a huge difference with sludge. I also feed a tiny carrot maybe once or twice a week. I give them green, red leaf, romaine, radicchio, cilantro & peppers as the main veggies and stay away from all of them that are high in calcium. I feed them unlimited hay; orchard grass or timothy.

I use to worry about the white spots too until I read this. Since the spots are powdery, I quit worrying.

**NOT NORMAL:
Gritty compounds: may indicate sludge in the bladder. Strong smelling urine may be a sign of dehydration or infection. The gritty deposits are sometimes called sludge, which feels coarse and sandy. Powdery deposits are normal. Rub the deposits between your fingers to determine if they are powdery or gritty. **

https://www.guinealynx.info/normal.html

@lunarminx , that GL info is outdated.

@NJPKL, you're in KMS territory, so shipping shouldn't be much, and you should be able to buy her pellets much cheaper than you can get Oxbow. They're the only ones I know of that don't use calcium carbonate (aka limestone) as their calcium source (there may be others that I don't know about, and I can't find an ingredients list for Small Pet Select pellets). That said, I had a pig with bladder stones that had been fed nothing buy KMS pellets since she came off Cavy Performance at six months old.

No one really knows what's "normal" in the way of visible calcium in the urine. What we do know is that excess urinary calcium is a factor in stone formation, and that some pigs will have stone problems and others won't. I've been reading every post I can find about guinea pigs and stones, and after about three years, I haven't found a pig with stones that didn't also secrete calcium, sometimes gritty, but sometimes powdery only.

So I'm putting my money on the fact that a diet low in calcium, with no visible urinary calcium if I can make that happen, is safer and healthier for my pigs than powdery urinary calcium.

Thanks everyone for the ideas and info! I am thinking of switching pellets to KMS since Oxbow has the high calcium, and maybe that will fix things up a bit. I read too that the white powder is not a worry, but I do worry anyway! Call me a overly cautious mama.