Pentair DE Filter Lower Tank Half | 24850-0102S
Pentair
SKU: 24850-0102S
Pentair / Sta-Rite 24850-0102S System:3 Lower Tank Half (21" Filter Tank Bottom)
The Pentair / Sta-Rite 24850-0102S is an OEM replacement lower tank half (tank bottom) for select Sta-Rite System:3 filter systems that use a 21-inch tank. This part restores the structural base of the filter and the sealing surface where the tank O-ring seats. It’s typically replaced when the original lower shell is cracked, warped, leaking, or the clamp interface is damaged.
Common Compatibility (Verify Your Filter Model)
- Sta-Rite System:3 Modular Media (SM series) – commonly listed for S7M120
- Sta-Rite System:3 Modular D.E. (SMD / SD series) – commonly listed for S7MD60, S7MD72, S7D75
- Sta-Rite System:3 Sand (SS series) – commonly listed for S7S50 (and often referenced on System:3 sand configurations)
System:3 parts vary by tank size (21" vs 25") and series. Confirm your tank size and exact model on the filter label and parts diagram.
What This Part Does
- Replaces the lower portion of the filter tank to restore leak-free operation
- Provides the seating surface for the tank O-ring and proper tank alignment
- Supports internal filter modules and plumbing bulkheads (model dependent)
When to Replace the Lower Tank Half
- Hairline cracks, stress fractures, or visible seepage from the tank bottom
- Warping/deformation that prevents the tank O-ring from sealing
- Damage at the clamp/locking interface that prevents safe, even clamping
- Recurring leaks after replacing the tank O-ring and cleaning sealing surfaces
Installation Notes
- Turn off the pump and relieve all pressure at the air relief before opening the filter.
- Inspect the tank O-ring and replace it if flattened, swollen, cracked, or nicked.
- Clean all sealing surfaces thoroughly; debris or scale can cause leaks even with new parts.
- Tighten the clamp evenly per manufacturer procedure (do not over-tighten).
- After restart, check for slow seepage once the system reaches full operating pressure.
Related Products (Aqua Pool Supply)
- 24850-0102S Lower Tank Half (Search)
- System:3 Tank O-Ring / Seal (Search)
- System:3 Clamp / Band Hardware (Search)
- System:3 Air Relief / Gauge Parts (Search)
- Pool-Safe Silicone O-Ring Lubricant (Search)
Maintenance Tips
- Always fully relieve pressure before opening the filter to protect components and sealing surfaces.
- Keep the tank O-ring clean and lightly lubricated with pool-safe silicone lubricant to reduce pinching and leaks.
- If the tank sits in direct sun, provide shade when possible to help extend plastic component life.
- Record your clean starting pressure after reassembly; a rising baseline can indicate restriction or system changes.
Questions about returns? View our return policy.
Hours Of Operation:
Monday - Friday: 7:00 am to 5:00 pm Phoenix Time
Saturday: 8:00 am to 2:00 pm
Sunday: Closed
- We do not ship on Saturday or Sunday.
- Orders totaling more than $300 will require signature confirmation upon delivery.
- We process and prepare orders for shipment within 1 business day. Please note that many other pool supply retailers require 3–5 days of handling time before shipping.
- Orders placed after 1:00 pm Phoenix Time may not be eligible for same-day shipment.
- Expedited shipping options are available at checkout.
Return Policy:
- Products that are received damaged will receive a refund in store credit.
- Most products are eligible for return within 30 days of receipt, except where noted below.
- To initiate a return, please complete an RMA form prior to sending your item back.
- Original shipping costs are non-refundable and will be deducted from the return credit.
- Items returned missing accessories or original packaging, or that are not in the same condition as received, may be subject to a restocking fee of up to 100% depending on the condition of the item upon return.
- Some returns will be charged an automatic 15% restocking fee.
- We are unable to issue refunds for items that have been damaged or rendered inoperable due to installer error.
- Please complete the return form to receive your RMA number and return shipping label.
- Chemical products are not eligible for return under any circumstances.
- The Pentair Colorsync 618031 is not eligible for return.
- Pool cleaners are not eligible for return.
- Opened seals and o-rings are not eligible for return.
- Capacitors are not eligible for return.
- Plastic popup tools are not eligible for return.
- Automation components and circuit boards are not eligible for return.
- If a light is returned due to a reported malfunction and is found to be fully operational upon testing, return shipping costs and a restocking fee will be deducted from the refund.
- Orders refused at the time of delivery will be subject to the original shipping costs being deducted from the refund.
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