Description
The Unicel PG-1903 is a single partial replacement DE filter grid for vertical grid DE filter systems with 36 square feet of total filtration capacity. Engineered to Unicel’s precise OEM dimensional standards, this partial grid features an open-slot collar with two notches for secure manifold engagement and is built with high-grade DE filter fabric and reinforced seaming for lasting pressure resistance.
IMPORTANT: PARTIAL GRID NOT A FULL GRID
This is a single partial DE filter grid, used alongside full grids to complete a filter set. Verify your filter model’s grid configuration before ordering partial grids are NOT interchangeable with full grids.
IMPORTANT: Full Grids Also Required This is the Partial Grid Only
Most 36 sq. ft. DE filters using this partial grid require 7 full grids + 1 partial grid for a complete re-grid service. This listing is for the partial grid only. You will also need Unicel FG-1003 Replacement DE Filter Grid.
Specifications
| Filter System Area | 36 sq. ft. (total system) |
| Grid Length | 18″ (measured end-to-end; collar not included) |
| Collar Configuration | Open slot, 2 notches |
| Grid Type | Partial grid (1 per filter system) |
| Material | High-grade DE filter fabric with reinforced seaming |
Note from Unicel: Collar has open slot (2 notches). Length is measured from one end of the grid to the other (collar not included).
Fits into:
| OEM Brand | Filter Model | OEM Part Number | Grid Configuration |
| Astral | 18045 Clarity DE | 7 full + 1 partial | |
| Hayward | Micro-Clear | DEX3600DS | 7 full + 1 partial |
| Hayward | Pro-Grid | DEX3600DS | 7 full + 1 partial |
| Pentair American Products | 5000 Series | 59001700 | 7 full + 1 partial |
| Pentair American Products | Titan CM | 59001700 | 7 full + 1 partial |
| Pentair American Products | Titan RPM | 59001700 | 7 full + 1 partial |
| Pentair American Products | Titan Stainless Steel | 59001700 | 7 full + 1 partial |
| Pentair Pac Fab | FNS 36 (Nautilus FNS Polymeric) | 19-2330 | 7 full + 1 partial |
| Pentair Pac Fab | FNS Plus | 59001700 | 7 full + 1 partial |
| Pentair Pac Fab | NS36 (Nautilus) | 19-2330 | 7 full + 1 partial |
| Pentair Pac Fab | NSP-36 (Nautilus Plus) | 19-2330 | 7 full + 1 partial |
| Waterway Plastics | Crystal Water | 818-3940 | 7 full + 1 partial |
(This is not an exhaustive list.)
Pro Tips
- Measure first: Confirm your existing grid is 18″ from end to end (collar excluded) before ordering. Different filter sizes use different grid lengths.
- Check your collar: Ensure your manifold accepts an open-slot, 2-notch collar. Inspect the collar and o-ring during each grid replacement.
- Safety first: Always turn off the pump and release all pressure from the filter tank via the air relief valve before opening the tank to replace grids.
- Complete your re-grid: This partial grid pairs with 7 FG-1003 full grids for a full filter service on most compatible 36 sq. ft. systems.
Also known as: PG1903









