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Oase Phosless Cartridges

SKU: 36981
$81.99

OASE Phosless Cartridges are phosphate-removing filter media designed for BioTec pressurized pond filters. These cartridges help control algae by removing excess phosphates from your pond water—one of the key nutrients that fuel algae growth. By reducing phosphate levels, you can achieve clearer water and better algae control.

Key Features:

  • Removes excess phosphates that fuel algae growth
  • Helps prevent green water and string algae
  • Easy to install in BioTec filter cartridge slots
  • Works alongside your existing filtration system
  • Safe for fish and plants
  • 2 cartridge tubes included per box

Why Remove Phosphates:

  • Phosphates are a primary nutrient source for algae
  • High phosphate levels lead to persistent algae problems
  • Removing phosphates starves algae, preventing growth
  • Complements UV clarification and biological filtration
  • Especially helpful in ponds with heavy fish loads or runoff issues

Compatible With BioTec Filters:

  • BioTec 18-36 (older models)
  • BioTec ScreenMatic² 18000 (model #42975) - uses 3 tubes
  • BioTec ScreenMatic² 24000 (model #44120) - uses 4 tubes
  • BioTec ScreenMatic² 32000 - uses 6 tubes
  • BioTec ScreenMatic² 38000 - uses 6 tubes
  • BioTec ScreenMatic² 39000 (model #93036) - uses 12 tubes

How Many Cartridges Do You Need:

  • BioTec 18000: 3 tubes (order 2 boxes for full replacement)
  • BioTec 24000: 4 tubes (order 2 boxes for full replacement)
  • BioTec 32000: 6 tubes (order 3 boxes for full replacement)
  • BioTec 38000: 6 tubes (order 3 boxes for full replacement)
  • BioTec 39000: 12 tubes (order 6 boxes for full replacement)

What's Included:

  • 2 Phosless cartridge tubes per box

Replacement Schedule:

  • Replace cartridges when phosphate removal effectiveness decreases
  • Typically every 4-6 months depending on pond conditions
  • Test phosphate levels to determine when replacement is needed
  • More frequent replacement may be needed in heavily stocked ponds

Note: Each box contains 2 cartridge tubes. Calculate how many boxes you need based on your filter model (see quantities above). Phosless cartridges work best as part of a complete filtration system including mechanical filtration, biological filtration, and UV clarification.

Frequently Asked Questions

Q: How do Phosless cartridges help control algae?
A: Algae need three things to grow: light, nutrients (primarily nitrogen and phosphorus), and water. While you can't eliminate light or water, you can reduce nutrients. Phosless cartridges remove phosphates (a form of phosphorus) from your pond water, starving algae of this essential nutrient. This is especially effective for controlling stubborn algae problems that persist even with UV clarification and good filtration. By reducing phosphate levels, you make it much harder for algae to thrive, resulting in clearer water.

Q: How many boxes do I need to order for my BioTec filter?
A: Each box contains 2 cartridge tubes. For the BioTec ScreenMatic² 18000, you need 3 tubes total, so order 2 boxes (you'll have 1 spare). For the BioTec 24000, you need 4 tubes, so order 2 boxes. For the BioTec 32000 or 38000, you need 6 tubes, so order 3 boxes. For the BioTec 39000, you need 12 tubes, so order 6 boxes. The cartridges install in the dedicated cartridge slots in your BioTec filter—consult your filter manual for exact placement.

Q: How often should I replace Phosless cartridges?
A: Replacement frequency depends on your pond's phosphate levels and how heavily stocked it is. Typically, cartridges should be replaced every 4-6 months. However, the best way to determine when replacement is needed is to test your pond water for phosphates. When phosphate levels start to rise again, it's time to replace the cartridges. Heavily stocked koi ponds or ponds receiving runoff from lawns (fertilizer contains phosphates) may need more frequent replacement. Keep spare cartridges on hand so you can replace them as soon as phosphate levels increase.