Order Helpline 01752 692 221

Marsh Uni:Gem Star Septic Tank Conversion Unit up to 6 PE for Spherical Septic Tanks

Product Code:
Est. Delivery: 7-12 Working Days
Shipping costs displayed in basket.
We can let you know when this product is back in stock.

This product is proving to be very popular and has unfortunately sold out.

Enter your email below and we'll notify you as soon as this product is back in stock:

Subject to stock availability, if products on a 24 hours service are ordered alongside products NOT on a 24 hours service, this may delay your whole order.

View Transport Policy

All delivery charges are included in the final shopping basket and are dependent on the products Scottish Highlands & the Islands where additional shipping charges will apply.

Please note that not all products will incur an additional delivery charge to the Scottish Highlands & the Islands – this is based on the costs from the manufacturer, distributor or courier providing shipping on our behalf. If your delivery address is in the Scottish Highlands and Islands, a member of our helpline team will contact you prior to processing your order should an additional delivery charge apply.

While we make every effort to ensure orders are delivered by the date required, we cannot guarantee availability from the manufacturer or the manufacturer's delivery schedules.

Any variation to web delivery date given will be advised to you by email or telephone. If we are unable to make delivery because access is not possible, we reserve the right to make a failed delivery charge.

£2,772.73 Incl. VAT
Oops! Please select from the options

Product Description

The Uni:Gem Star, is a unique septic tank conversion unit which exceeds EN12566-3 / EN12566-6 standards and conforms with 2020 General Binding Rules (GBRs for septic tanks or small sewage treatment plants for domestic use). The UG-SPH model has been designed specifically for spherical ‘onion’ shaped septic tanks.

The Uni:Gem Star conversion unit is an extremely cost-effective solution for converting any polluting septic tank into a fully compliant sewage treatment plant. This, along with ease of installation, ensures homeowners, estate managers, water companies/amenities all have an effective way to keep the environment clean.

With two models to choose from, both of which have been designed to suit different types/shapes of septic tanks, the Uni:Gem Star treats the septic tank discharge to an effluent quality of BOD 12.25:TSS 16:Ammonia 14.845 mg/l, meaning final effluent can be discharged safely to a river, ditch or watercourse.

Please ensure you check your septic tank outlet invert (ground level to the bottom of the pipe).

How does the Marsh Uni:Gem Star work?

The process begins with effluent from the existing septic tank or sewage treatment plant being transferred to the Uni:Gem Star unit via the inlet. It then enters the aeration chamber where it is treated to remove dissolved constituents. Here aerobic bacteria, supported by diffused air and mobile media, ensures full treatment is achieved before the treated effluent flows to a final settlement chamber prior to discharge.

Features & Benefits

  • Converts a polluting septic tank into a fully functioning sewage treatment plant without the need for removing/replacing the old tank
  • Tested to EN12566-3 / EN12566-6 and CE-marked to ensure compliance with environmental and Building Regulations requirements
  • Outstanding effluent quality of 12.25:16:14.845 (BOD:SS:NH4)
  • Tested and proven to be suitable for all ground conditions, all year round
  • Provides a space saving solution for sites
  • Low energy compressor ensures minimal running, maintenance and servicing costs
  • Quick and easy installation process ensures cost-savings
  • Provides simple and safe access for maintenance and cleaning
  • Uni:Gem Star’s GRP material passed all practical testing to achieve EN ISO 11925-2:2010 standard
  • Integral lifting eyes for improved on-site handling
  • Final effluent is clear and odourless


Width (Diameter): 1512mm

Height: 2540mm

Population: up to 6 People

Material: GRP

Inlet invert: 1040mm

Inlet Diameter: 110mm

Outlet Invert: 1140mm

Outlet Diameter: 110mm


Material GRP

Products We Recommend


Questions & Answers

There are currently no questions for this product.

Product Enquiry Form

Marsh Uni:Gem Star Septic Tank Conversion Unit up to 6 PE for Spherical Septic Tanks

*Required Field

Would you like to empty your basket?

Yes No


It seems you are running an older version of Internet Explorer. Our site does not support these old browsers as they do not house the technology that allows our site to be safe and secure.

If you wish to access our site please either upgrade your browser or download an alternative.