Product Information
Description
Light Doctor 6-Hole Niche Disc Enclosure
Small niche. Permanent fix.
The Frank Wall Enterprises Light Doctor TLD6D (PST-57-256-1060) is a 6-hole Lexan® disc enclosure that permanently seals small pool light niches and spa light niches on vinyl liner builds. It bolts to a 6-hole pattern with 5-5/16" hole-to-opposite-hole and 2-7/8" adjacent spacing, and installs in front of or behind the liner. It cross-references OEM parts 3503-010 and 389453, so the failed disc comes out and the new one bolts straight in.
Built to Outlast the Pool
You get a single piece of Lexan® polycarbonate instead of a stacked gasket repair. Lexan shrugs off chlorine, salt, UV, and the freeze-thaw cycle that finally killed the original niche, so the wall stays sealed long after the failed fixture is gone. Backed by a 12-month manufacturer warranty, this is the part that ends the leak instead of postponing it.
Drop-In 6-Hole Fit
Use a tape measure on the existing niche before you order. Hole to opposite hole should read 5-5/16" and adjacent holes should sit 2-7/8" apart on a 6-hole pattern. If you already have OEM 3503-010 or 389453 on the parts tag, this disc is the direct replacement and bolts onto the original screw holes without re-drilling.
Pool and Spa Niches
Unlike the larger 8 and 10-hole discs, the TLD6D covers two jobs at once. The same Lexan® disc seals small 6-hole pool light niches and the 6-hole spa light niches common on attached spas and standalone vinyl spas. One part fits both, so you can fix a leak on either side of the equipment pad with the same item.
Who It's For
Small Pool Light Niches
Engineered for the small 6-hole niches found on vinyl liner pools, especially older builds with single-bulb wet-niche fixtures.
Spa Light Niches
Also fits 6-hole spa light niches on attached spas and standalone vinyl spas, where the niche is too small for a standard pool disc.
Damaged Niche Repair
Replace a cracked, leaking, or corroded 6-hole niche with a single sealed disc instead of cutting open the wall.
OEM Cross-Replacement
Direct drop-in for OEM parts 3503-010 and 389453, both common 6-hole niche discs on legacy vinyl builds.
Why PST Customers Pick This
Stops Niche Leaks
Replaces a failed light housing or gasket stack with one sealed disc, so water stays in the pool instead of behind the liner.
Pool or Spa
The only Light Doctor disc that handles both small pool niches and spa niches, so one part covers both fixes.
Lexan® Hardness
Polycarbonate stands up to chlorine, salt, bromine, and pH swings far better than ABS or acrylic discs sold for the same job.
Verified by Measurement
Published 5-5/16" and 2-7/8" hole dimensions let you confirm fit before ordering, no guessing on legacy niches.
Original Bolt Pattern
Uses the existing 6 mounting holes, no drilling, no enlarged openings, no permanent damage to the niche flange.
Frank Wall Quality
Built by Frank Wall Enterprises, the brand pool and spa techs use when they want a niche problem to stay fixed.
Installation Notice
This disc seals a wet-niche penetration in your pool or spa wall. A poor seal can drive water behind the liner and rot the wall structure. If the original light circuit is still live, kill the breaker and verify zero voltage at the niche before you touch it. If you are not comfortable bonding the niche per NEC Article 680 and inspecting the liner attachment, hire a licensed pool service technician.
Full Specifications
Frequently Asked Questions
What is the difference between the 6-hole, 8-hole, and 10-hole Light Doctor discs?
The number refers to the bolt pattern on your existing light niche, not the disc itself. Count the screws around your niche or the empty bolt holes if the fixture is already out. If you count 6 holes spaced about 2-7/8" apart, with 5-5/16" from a hole to the hole directly across, this TLD6D 6-hole disc is the right part. Wrong hole count means a different disc, so verify before ordering.
Will this work on a spa as well as a pool?
Yes. The TLD6D is the one Light Doctor disc designed for both small 6-hole pool light niches and 6-hole spa light niches. If your spa light is leaking or you're retiring the fixture, this is the disc to use as long as the bolt pattern matches the 5-5/16" and 2-7/8" measurements.
Does this replace OEM parts 3503-010 or 389453?
Yes. The TLD6D is a direct drop-in for both 3503-010 and 389453, two of the most common 6-hole light niche discs on older vinyl liner pools and spas. Match the bolt pattern, confirm the measurements, and the disc bolts onto the existing screw holes.
Will this work on a concrete or fiberglass pool?
No. The TLD6D is engineered for vinyl liner pools and spas only. Concrete, gunite, and fiberglass niches use different sealing methods and require purpose-built closure rings or a replacement fixture.
Can I install this myself?
Many vinyl liner owners install the TLD6D themselves with the pool or spa partially drained below the niche. Kill the light circuit at the breaker, remove the failed fixture, clean the niche flange, then bolt the disc to the existing 6-hole pattern with stainless niche screws. If you are not comfortable working at a wet niche or interpreting bonding requirements under NEC Article 680, have a licensed pool technician do the install.
Do I install it in front of the liner or behind it?
Both are correct, you choose. Mounting in front of the liner is faster and fully serviceable, which works well if you may revisit the niche later. Mounting behind the liner hides the hardware for a cleaner wall, but is usually done during a liner replacement when you have access to the flange before the new liner goes in.
Does it include screws or a gasket?
The TLD6D ships as the Lexan® disc only. Most installers reuse the existing niche fasteners and add a fresh bead of pool-rated silicone or butyl sealant at the disc-to-niche contact face. If the original screws are corroded, replace them with new stainless niche screws before installing the disc.
Order the TLD6D From PST
Authorized Frank Wall Enterprises dealer. Backed by PST Pool Supplies' service team, with help on the line before and after your install.
Additional Info
| Category | Parts Pool Parts Pool Light Parts |
| SKU | PST-57-256-1060 |
| MPN | TLD6D |
| Replaces | 3503-010, 389453 |
| Manufacturer | FW Enterprises |
| Weight | 0.26 lb |
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Very good customer service. The post office screwed up my order and they responded to my msg very quickly and reshipped another part free of charge. 👍👍
I was looking for a part for an old pool filter housing.
Fortunately, I found PST. They had the part and I ordered it on a Friday, and it arrived on Tuesday by FedEx.
The filter housing was updated and different, but once I installed it, it fit perfectly and worked just as it should. I am so pleased with not only the part that I received but also the expert service and at a fair and excellent price.
Thank you, PST Pool Supply, for coming to my rescue. I highly recommend you checking with PST for your pool needs!
Replacement part was correct and vacuum is back together and being used.
Easy fix for small leak around valve in concrete pool.
Definitely recommend this shop!
We are running big and deep pool and we get all what we need from here
I had trouble finding the right part that would fit. PST helped me figure out exactly the right part and fit.
Helped me get my light installed correctly after liner change
This machine cleans 10 times better than my previous one and is worth the cost. However, I’ve only had it for 2 weeks. The last one lasted about 6 months and never cleaned well even though it had 4 stars when I bought it. I hope this new one remains strong for a few years
The pump was a great value and it was described perfectly. The product was shipped fairly quickly and it was well-protected
After much research the value of the product is good. It was shipped fairly quick and it arrive in a well-protected package.
Very happy with this purchase fits and work as described fast shipping
Loved how fast it got here. It has small wiring and I was glad it was in a protective envelope and it arrived without breaking.
