Pentair Sand Dollar Sand Filter

The Sand Dollar is Pentair's top mount sand filter, a one-piece thermoplastic tank with a multiport valve clamped to the top. Pentair's brochure covers five sizes, from the SD 35 to the SD 80, and there's an SD 80 with ClearPro Technology. The Cristal-Flo II shares the same manual and most of the same internal parts.

Which sizes are current depends on which Pentair document you read. The 2025-2026 catalog lists four: the SD 60 (145322), SD 70 (145367), SD 80 with a 1.5 in. valve (145333) and SD 80 with a 2 in. valve (145386). The product page lists 145315, 145320, 145322, 145367, 145386 and the online-only EC-145322, without naming models.

Which size

From Pentair's brochure, each with its maximum flow rate and the sand it takes:

• SD 35: 1.40 sq ft, 35 gpm, 100 lb of sand, 16.5 in. tank
• SD 40: 1.80 sq ft, 40 gpm, 150 lb, 19.5 in. tank
• SD 60: 2.30 sq ft, 60 gpm, 250 lb, 22.5 in. tank
• SD 70: 3.15 sq ft, 70 gpm, 300 lb, 24 in. tank
• SD 80: 3.50 sq ft, 75 gpm, 350 lb, 26 in. tank

The flow figure is a maximum, so don't put a pump on the filter that pushes more than that. The manual says to size the system to turn the pool over at least twice every 24 hours. The brochure's turnover columns show what each size handles at full flow over 8, 10 and 12 hours: 43,200 gallons for the SD 60 over 12 hours, and 54,000 for the SD 80.

Leave headroom above the filter. The brochure gives the vertical clearance needed to lift the valve out, from 36.75 in. on the SD 35 to 73 in. on the SD 70 and 74 in. on the SD 80. Under a low roof, that's the size limit.

Pentair's catalog gives the SD 60 a 40 psi maximum pressure and the SD 70 and SD 80 50 psi. The manual says the maximum is on the filter's name plate and not to connect a pump that can exceed it. Pentair's catalog and its ClearPro page both give a maximum water temperature of 95°F.

ClearPro

The ClearPro version adds a porous tube inside the tank that water passes through before it goes back to the pool. Pentair says traditional sand filters stop particles in the 50 to 100 micron range, and that ClearPro removes particles up to five times smaller. It also claims clarity 60% better than other sand filters, and matching D.E. These are Pentair's claims, not tested here. The brochure lists one ClearPro model, the SD 80 CP, with the SD 80's area, flow and sand. Its laterals are their own part, 150088.

Sand

The manual is specific: No. 20 silica sand, particle size 0.018 to 0.022 in. (0.45 to 0.55 mm), with a uniformity coefficient of 1.75 or less. Use the exact amount on the name plate.

1. Look inside the tank first for broken or loose laterals, which can be damaged in shipping.
2. Fit the sand guide in the top and fill the tank about half full of water.
3. Pour the sand in slowly, so its weight doesn't break the laterals.
4. Remove the sand guide, and wash all the sand off the top opening.
5. Check the valve's O-ring is in place, push the valve firmly into the tank so the two flanges touch, and fit the clamp. The nuts sit in the clamp's hexagonal slots. Tighten the screws firmly.

Plumbing: use a sealant made for plastic pipe on tapered threads, and no petroleum-based products. The manual says all the valve's internal threads are tapered except the air bleeder's, and to go hand tight plus one turn. The pressure gauge goes in the 1/4 in. NPT port across from the pump port.

Starting it up

1. Set the valve to Backwash, with the backwash line open. Open the air bleeder, stand clear, and start the pump. Close the bleeder when a steady stream of water comes out.
2. Once water runs steadily out of the waste line, backwash for at least two minutes to flush the fine particles out of new sand.
3. Pump off, valve to Rinse, pump on, for at least two minutes.
4. Pump off, valve to Filter. Open the bleeder, stand clear, start the pump, and close the bleeder once it runs water.
5. Write down the pressure. That clean-filter reading is what you'll compare against from now on.

On a new pool, the manual says to backwash and clean the filter after the first 48 hours of running, to clear construction debris.

When and how to backwash

The manual gives three ways to tell, from most accurate to least:

• A flow meter: backwash when flow has dropped 30% from the clean-filter flow.
• The returns: backwash when the flow coming out of them visibly drops.
• The gauge: backwash when it reads 10 psi above the clean reading. The manual calls this the most common method and the least accurate.

It also says not to backwash on a schedule, and that backwashing too often makes filtration worse.

To backwash:

1. Stop the pump. Open the suction and backwash lines, and set the valve to Backwash.
2. Stand clear and start the pump. Backwash for about 3 minutes, or until the water runs clean.
3. Stop the pump, set the valve to Rinse, and rinse for about 30 seconds.
4. Stop the pump and set the valve to Filter. Open the air bleeder, stand clear, start the pump, and close the bleeder when it runs water.

Always turn the pump off before moving the valve handle. The manual says moving it under flow can damage the valve. Our backwashing guide compares these times with Hayward's and Jandy's.

If the pressure after a backwash is still 4 to 6 psi above your original reading, the manual says the sand bed needs a chemical clean. Drain the filter, set the valve to Backwash, and with the pump running, pour a filter cleaning solution slowly into the pump strainer until the bed is saturated. Switch off, leave it in Backwash overnight, about 12 hours, then backwash as normal. Don't let the solution get into the pool.

Valve positions

• Filter: normal filtering, and vacuuming through the filter.
• Backwash: reverses flow through the sand and out the waste port.
• Rinse: forward through the sand, out to waste, to resettle the bed.
• Waste: bypasses the filter to waste, for vacuuming straight out, lowering the water or draining the pool.
• Closed: no flow. The manual says never to use it with the pump running.
• Recirculate: bypasses the filter and returns water straight to the pool.
• Winterize: where the valve sits over the winter.

Winterizing

1. Backwash the filter, switch off the pump, and set the valve to Winterize.
2. Remove the drain port cap at the bottom and let the filter drain slowly. Remove only the cap: taking out the whole fitting lets the sand drain too. Store the cap until spring.
3. Drain the system piping.
4. Cover the pump and filter with a tarp or plastic sheet, but don't wrap the pump motor.

Leave the valve in Winterize all season. The manual says any other position leaves pressure on the diverter's rubber seal, which can damage it and cause leaks. Where the pump can't be drained, it allows a 40% propylene glycol solution, and no other antifreeze.

Troubleshooting

From the manual's table:

• Water not clean enough: chemistry that isn't holding back algae, backwashing too often, the wrong amount or size of sand, or too little running time.
• Pressure higher than normal: not backwashing enough, mineral deposits plugging the sand bed, or a partly closed valve or other restriction on the return.
• Short filter cycles: poor backwashing, chemistry, a plugged sand bed, or flow above the filter's rating. For a plugged bed, the manual says to scoop out the top inch of sand and chemically clean it.
• Weak return flow with low filter pressure: a clogged pump basket, pump or suction line.
• Sand in the pool: a broken lateral, or a backwash rate that's too high.

Parts

Pentair publishes three Sand Dollar parts lists, and they don't all agree:

• The manual (P/N 152006 Rev. D, 2017) has the filter's parts, with the Cristal-Flo II's tanks alongside, and full breakdowns of both the 1.5 in. and 2 in. valves. Its French and Spanish lists carry the same numbers.
• The parts sheet for blow molded filters, from Pentair's parts catalog, adds the earlier almond laterals, earlier piping assemblies and the complete drain assembly.
• Pentair's 2025-2026 catalog, updated June 2025, reprints that sheet with a Z added to several numbers, and drops the earlier piping and the SD 35's almond lateral. It leaves blank rows where the drain cap, the sand drain and the SD 35, SD 60 and SD 80 tanks were.

The list below gives every number from all three, with a note wherever they differ. Pentair also publishes separate parts sheets for Sand Dollar filter systems, the above-ground packages with a pump and base. Those aren't covered here.

Where Pentair's documents disagree

• The SD 40's foot. The manual gives 154926 for the SD 35 and SD 40. The parts sheet and catalog give 154926 for the SD 35 only, and put the SD 40 on 154520 with a footnote saying it was used on filters made before February 2002.
• The 2 in. valve's union kit. The manual gives 272590Z. The parts sheet and catalog give 272569.
• Part 272541. Everywhere else it's the valve body O-ring. The manual's 2 in. valve table also lists it as that valve's diffuser, in all three languages, while giving the 2 in. valve body O-ring as 274402Z.
• Which models are current. The catalog lists the SD 60, SD 70 and both SD 80s. The product page lists two more item numbers, 145315 and 145320, and leaves out 145333, the SD 80 with a 1.5 in. valve that the catalog and TradeGrade list both carry.
• The SD 70's turnover. The catalog gives 54,000 gallons over 12 hours. The brochure gives 50,400, which is what 70 gpm for 12 hours comes to.
• How many positions. The product page and brochure call it a six-position valve. The manual describes a seventh, Winterize.
• Maximum pressure. The catalog gives 40 and 50 psi. The manual only says it's on the name plate.

Buying it

Pentair gives filters two years when bought from a dealer and professionally installed. The EC-145322 is the version made for online sale, and the warranty page gives online purchases one year, parts only, with no labor. For a filter you'll install yourself, the manual's installation, sand and plumbing steps above are the ones to follow.