Summary
In December 2015, Hydrorelax founder Jonny visited GPP in Bremen, Germany — an e-commerce customer already assembling bathtub jets, drains and PVC fittings from Hydrorelax. Walking the warehouse and assembly bay first-hand shaped how we package and support European e-commerce partners today.
On December 8, 2015, Hydrorelax founder Jonny landed in Bremen, Germany to visit GPP, a local e-commerce customer that had already been buying bathtub jets, drains and PVC fittings from Hydrorelax and selling spa parts and bathtub products on Amazon DE and other European marketplaces. By the time of the visit, our parts were already on the shelves and going through the GPP assembly line. The point of going in person was to see those parts in their working environment — how GPP stocks them, assembles them, water-tests them, packs them, and ships them to European end consumers. This article walks through what we saw inside the GPP warehouse that day, and what the trip meant for Hydrorelax's wider European push.
Hydrorelax and GPP started working together in 2015. By the time Jonny flew to Bremen on December 8, 2015, GPP had already placed orders and received our bathtub jets, drains and PVC fittings at their warehouse. The reason for going in person was simple: after the parts had landed and were being used on the GPP assembly line, we wanted to see them in real working conditions — meet the team, walk the warehouse, and understand how the products were being consumed.
GPP's owner, Grenz, met Jonny at the warehouse. Within the first hour it was clear that GPP was not a traditional importer — it was a working e-commerce operation. Half-assembled tubs and parts come in from overseas suppliers, get finished and water-tested in Bremen, photographed in an in-house studio, and shipped out to European end consumers via Amazon DE and other online channels.
The GPP warehouse runs as a hybrid stocking + light-assembly + fulfillment space. The main aisle is lined on one side with light shelves of small SKUs (with amazon.de labels visible on many boxes), and on the other side with finished white-goods and bulk inventory staged on pallets. Picking carts move down the centre, and there is no clutter on the floor.
Walking the aisle, Jonny could see the operation was tuned for online order velocity rather than wholesale loads — many small picks rather than a few large outbounds, with every SKU clearly labeled for the marketplace it serves.
A big part of GPP's value sits in what happens between receiving and dispatch. Bathtub shells come into the warehouse half-assembled and palletised. Beside them, GPP keeps stocked boxes printed with model codes such as XMA-32, XMA-14, XMJA-1 and XMJA-39, each holding the matching set of parts. PVC hoses, jets and drain fittings sit in nearby cartons, ready to be drawn into the next assembly.
In the assembly bay the workflow is straightforward: a tub shell is placed on a working frame, the PVC water-line loop is fitted underneath, jets and drains are mounted on the inside, then the unit is water-tested before it moves on to packing. The image below shows one of the finished corner whirlpool tubs — jets in, PVC manifold built up, control cable run, ready for final inspection.
For Jonny this was the most useful part of the visit. Seeing the half-finished tubs lined up next to coiled hoses and pre-kitted boxes made it obvious which jets, drains and PVC fittings GPP actually consumes most — and which spec points (thread compatibility, hose diameter, gasket fit) matter when those parts arrive after a long sea shipment from China.
German marketplaces are strict about packaging. The orientation labels on the white-goods near the main aisle — DO NOT TOPLOAD / NICHT STAPELN — are a reminder that anything not clearly marked can end up stacked or handled the wrong way in transit. Outer cartons need to spell out orientation, fragility and handling expectations in unambiguous terms.
At the packing station, GPP keeps pre-folded corrugated boards sorted by size on the shelves, with a laptop running the scanning workflow and small accessory parts laid out on the bench for repacking. Every outbound order gets repacked into a box matched to its actual SKU dimensions — no oversized cartons, no loose fill swimming in empty volume.
From a supplier's side, this is concrete feedback we can act on. When Hydrorelax ships jets, drains and PVC fittings to Bremen, the inner cartons need to fit GPP's pick-and-pack flow without forcing them to break bulk into different boxes. After seeing the packing station in person, we knew exactly what carton sizes and labelling style to align with.
The 2015 Bremen visit gave Hydrorelax three things at once. First, a clear view of what a European e-commerce assembler actually needs from a Chinese components supplier — not just the parts, but the carton sizes and the labels. Second, direct exposure to the rhythm of a marketplace like Amazon DE, where a missing FRAGILE sticker or a wrongly-marked orientation can trigger a return that erases the margin on ten units. Third, a real working relationship with Grenz and the GPP team that we have continued to build on since.
From a global-layout point of view, GPP became one of the early reference points for how Hydrorelax serves European customers. The lessons from Bremen — on packaging discipline, on stock-vs-assembly split, on listing-photo quality — informed how we later structured component support for partners in other European markets too.
Looking back at the December 2015 trip, four things stand out:
The Bremen trip was the first of many European customer visits for Hydrorelax. As more spa-parts assemblers and online retailers across Germany, the Nordics and Eastern Europe move toward the GPP model — small-batch local assembly, marketplace-driven distribution — we keep adapting our component packs, carton sizes, labels and lead-times to fit. We look forward to continuing the partnership with GPP for many years to come.
We welcome European e-commerce customers to work with Hydrorelax. Beyond supplying bathtub jets, drains and PVC fittings, we provide ongoing technical support for assembly, water-testing and after-sales questions. Our CEO Jonny personally visits partner customers in Europe every year to give hands-on guidance on the shop floor, review the product mix, and sit down face-to-face to plan the next stage of cooperation.
If you run an online spa or bathtub business anywhere in Europe and want a components supplier who understands your working reality — not just a catalog vendor — get in touch. We are happy to start with a short call, ship samples, and plan the first visit together.
Who is GPP and what does the company do in Bremen?
GPP is a German e-commerce customer of Hydrorelax based in Bremen. The company keeps a local warehouse, an in-house assembly area and a photo studio, and sells spa parts and bathtub products on Amazon DE and other European online marketplaces. Half-assembled tubs and components ship in from suppliers like Hydrorelax, and final assembly, water-test, listing photography and dispatch all happen in Bremen.
When did Hydrorelax start supplying GPP?
Hydrorelax and GPP started working together in 2015. By the time Jonny made his first in-person visit to GPP on December 8, 2015, our bathtub jets, drains and PVC fittings had already been delivered to the Bremen warehouse and were being used on the GPP assembly line. Hydrorelax ships these components from Hangzhou to Bremen.
What products does Hydrorelax supply to GPP?
Hydrorelax supplies bathtub and spa accessories to GPP: jets, drains and PVC fittings. These components feed into GPP's local assembly line in Bremen, where they are fitted to bathtub shells, water-tested, and packed for European consumers.
What kind of packaging do German e-commerce buyers expect?
German marketplaces have strict expectations for outer packaging: clear orientation labels (often in German, such as NICHT STAPELN — do not stack), reinforced cardboard with the right flute thickness for the weight inside, and FRAGILE labels. GPP keeps pre-cut cardboard sorted by size at the packing station so each SKU is repacked in the right box for shipment.
Why did Hydrorelax visit a customer's German warehouse in person?
Visiting a customer in their own market is the fastest way to understand what they actually need — their products, their stock pressure, their packaging rules and their end consumers. The 2015 Bremen trip helped Hydrorelax see European e-commerce realities first-hand, and shaped how we work with all of our European customers since.