Just put 90 lbs (18 bags) in a new tank, which is cycling presently. So far I am very happy with this substrate. I shopped around for months to try to find a red aquarium-grade sand which I liked--- I came up empty, and even had trouble buying Aqua Terra at a price-point I liked. (I bought it at around $8.25 per 5-lb bag, or roughly $1.65/lb.) The price for red Aqua Terra sand seems to range from $2/lb to $3/lb, or more, both locally and online. I found it at a few other shops for less ($1.25/lb was the lowest) in bulk orders (cases of 6 bags, 5/lbs each), but absolutely NONE of these lower prices reflected actual in-stock availability--- in other words, online vendors took my money (hundreds) and were unable to fulfill the orders, leaving me to demand (and fight for) refunds after the fact. This delayed the establishment of my new tank.I ordered 18 bags on Amazon, and while there were some delays in fulfillment, everything arrived within a week and a half or so. (Ordered 10/26, and tank is fully set up by 11/5. My order arrived in three shipments.)A lot of the reviews for the sand criticized it for "floating" and "balling up". I can only assume that these reviewers have never used aquarium sand before, or else were adding it to an established tank (e.g. already full of water and fish) without experience in how to do so.Yesterday I put all 90 lbs of sand in my tank, and today the water is crystal clear and totally settled. I did not need to rinse each individual bag (5/lbs each), although I originally intended to. Below is an account of what I did.As I was establishing a NEW tank, rather than adding this substrate to an existing and occupied tank full of water, I did not need to worry so much about the "cloudy and clumpy" sand issue. Establishing a new tank is not an instant thing. If you want an instant thing, download an app that lets you take care of digital fish. Real fish, and real aquariums, are things requiring patience, discipline, and care: even water treatments (e.g. ammonia reducers) take 48-hours to take effect. Expecting bone-dry sand to be suddenly perfect and still in the water is... naive, and absent understandings of either aquarium dynamics OR basic natural sciences. But anyway. I digress.I researched the best ways to rinse large quantities of aquarium sand because I'm actually fairly new to aquarium keeping (I have less than 2-years experience) and didn't want to make assumptions. I spent a few hours rinsing 5-lbs of sand as per a YouTube video which showed a method of doing so in a plastic bottle. This worked great for rinsing the sand, as bags of sand or abrasive materials ALWAYS carry dust and particles which can cloud the water in a tank or rise (as a film) to the surface. However, it was NOT terribly effective for adding sand to a NEW tank, not already full of water: it would be the best way for adding substrate to a full and established tank, but not a new one. After the first 5-lbs of sand was rinsed, I abandoned this method......and I proceeded to just empty the remaining 85-lbs of sand into the (empty) tank. I added water in 12-gallon intervals, and the sand soaked up, and eventually was submerged. As I continued adding water, some of the sand "rose" to the surface, thick and frothy like the foamy head on a good pint of Guinness (or like red-colored shaving cream, for those who don't drink real beer). This was alarming, but I was at this point committed to continuing the process, because what else was I going to do?I filled the tank to about 100-gallons (not at all full, but "full enough"). At this point, MOST of the sand was at the bottom of the tank where it should be, however there was a "half inch" of sandy foam at the top of the water, floating. This wasn't really a half inch of sand, but rather, a half inch of sand "foam", or air-bubbles containing large clumps of sand and sand film. It looked like every mixing bowl of ingredients I have ever put together in the kitchen before baking, prior to mixing it. So, naturally, I mixed it.I used the curved "hoop" at the end of my aquarium net as a whisk, just like in the kitchen, and stirred the surface of the foamy sandy water. About five or ten minutes later, the water's surface was clear. All of the foamy sand had settled. I rejoiced. The water was still cloudy, but being somebody who has been to the beach more than once in my life, I expected this: dry sand + water = cloudy water!Next I noticed lots of air bubbles in the sand at the bottom of the tank. "Of course", I realized, "the sand is still dehydrated, and full of air!". So I washed my hands, rolled up my sleeves, and reached in to "squeeze" and "massage" the substrate in the tank. I went side to side, end to end, sifting the sand at the bottom of the aquarium--- like sifting for gold in a stream, or cleaning a cat-box, except that there was no gold or cat-waste, and all of the sand was released from my fingers.Naturally this filled the water with clouds of sand. And the foamy surface at the top? It came back.Thankfully I'd already learned at that point that the foam at the surface just needed to be whisked, again like virtually anything mixed together in a baking bowl in the kitchen. So I did that. Magically, all of the sand settled... foam and film? Gone, resolved. Surface clear.The clouds in the water remained, because hey guess what, I poured 100-gallons of water onto 90-lbs of dry sand coated in red acrylic. Clouds are sort of expected.24-hours later the water is crystal clear. The sand immediately underneath my Eheim 600 classic canister filter's "out" tube (e.g. the substrate hit with the filter's return line of pressured water) was smooth and perfect looking, while the rest of the tank still looked a bit "fresh", with the sand forming small clumps and such at the bottom. This is not unexpected. It is sand. Coated in acrylic. It'll take a bit of time to totally acclimate to being a submerged material. That's. . .that's how this works.So, admittedly, it has only been 24-hours. But after wasting a few hours rinsing 5-lbs of sand, and then spending less than 20 minutes stirring and massaging the full 90-lbs of sand in water, I have a crystal-clear tank with sand well on its way to being perfect.The tank is still cycling. The cycle, which is done to establish the healthy bacteria in the tank necessary for the biologicals it will house, will take 3-5 weeks. I'll keep an eye on it twice a day in the meantime, and update here if anything with the sand goes disastrously wrong--- but so far I can't imagine that it will.While far more expensive and challenging to acquire than I expected or cared for, the red Aqua Terra sand from Worldwide Imports has (so far, fingers crossed) performed beyond expectations, and I'm more than happy with it. I can't imagine why so many other reviewers were having the problems that they were--- it literally just took a little bit of stirring and squeezing to settle the sand. (If you're adding this sand to a tank already filled with water, look up a You Tube video for rinsing the sand in a plastic bottle, rather than a bucket or a bag, with a young British-sounding narrator; this would be the easiest way that I can think of to reduce clouds/clumps, and add the sand effortlessly and DIRECTLY to the base of your tank, by dispensing it directly from the bottle right to the bottom of the aquarium rather than pouring it at the surface of the water.)