The crate arrived on a Tuesday morning, and the system was the wrong shape for the alcove it had been ordered for. Fourteen millimetres too deep on the return wall. Not enough to spot on a spec sheet, plenty enough to matter when the client's joiner arrived the same week.
The short version, before the detail. Choose the size from the alcove and the chamber count rather than from the model number, because a model number is a product code, and codes do not measure anything. Then check the included-equipment list against the crate before the van leaves, because "complete set" means complete against the manufacturer's own list, and that list is rarely the list a running reef actually needs.
Two numbers on the box, and neither of them is the size
HB300, HB350, HB400, HB500, HB600S. Reading that ladder, most buyers assume the number is a volume or a length. The listing does not say either, and I have been burned once by assuming.
What the listing does say is a volume band covering the whole range: 28 to 72 litres, or 7.40 to 19.02 gallons. Two power options are listed, 8 W and 13 W, which at least tells you the range spans a meaningful step in equipment rather than a cosmetic size change.
So your first job, before any price conversation, is to ask for a dimensioned drawing per model. Skip the photographs and the renders. External footprint, height including the light, the width of the rear chamber, and the service clearance needed to accomodate the lid opening. Four numbers. Any supplier who cannot produce those four numbers for a specific model is selling you a picture.
Reading the model ladder backwards
Here is the order I use now, and it is the reverse of how these ranges are usually sold.
Start at the alcove. Measure the depth available, subtract the cable and hose clearance at the rear, and that gives you your maximum external depth. Nothing downstream matters until that is fixed, because a tank that does not fit costs you a return and a client.
Then look at the rear chamber. On this range it is described as a three-compartment back filter with an oil film removing function. Three chambers is a working number, because the first holds mechanical filtration, the second is where the skimmer sits, and the third is where the return pump lives. If the chamber depth is tight, the skimmer you actually want will not go in, whatever the listing says about the skimmer being included.
Display volume comes last. Buyers talk about litres first and it is the least binding constraint of the three.
What the complete set actually contains
Ruibit's listing for this range is unusually specific here, and it is worth taking at face value because it is the part you will be checking against the crate. Five items ship as the set:
Two observations from that table, both worth raising with any supplier before you order.
Five items are named and then the list stops. A heater is not on it. Neither is a wave maker, an auto top-off, salt, test kits or a stand. That is normal for this category rather than a fault, but it means "complete set" is complete against a packaging list and not against a working system. If your end customer expects to fill it and run it, price the missing pieces into your own retail figure or you will be absorbing them on the phone.
That carton figure is a single 50 × 50 × 50 cm box at 30 kg gross, quoted across a range spanning 28 to 72 litres. That is a 2.6-fold difference in water volume. Ask which model that carton describes, and ask for the carton per model. Freight and warehousing are budgeted on this line, and a wrong carton figure is a wrong quote.
Size it from the alcove, not from the model name
Worked example, and I will flag it as one because the per-model split is not published. Take three end uses and see where the band lands.
Two of those columns decide it. Volume follows the alcove and the chamber, not the model suffix. When a buyer asks me which of HB300 to HB600S to stock, my answer is usually to stock two sizes with a real gap between them, because a range stocked top to bottom cannibalises itself and doubles the spare parts you have to hold.
Checking the crate before the van leaves
This is the part that pays for itself. Everything below takes about forty minutes on a first order.
- Count the crate against the five-item list, item by item, with the packing list in your hand. Do not count from memory; the skimmer is the item that goes missing most often because it ships loose in the chamber.
- Photograph the crate before opening and after opening. Damage claims with a carrier are won or lost on those two pictures.
- Weigh one unit. Listed gross is 30.000 kg. A significant deviation tells you the carton has been re-specified without the listing being updated.
- Power up a single unit on the bench. Run the pump and the LED for an hour and listen. A pump that is quiet for the first ten minutes and noisy at sixty is the failure you will see in month four.
- Check the glass and the chamber joints in daylight, along the full length of the front viewing panel and every chamber wall.
- If the order is larger than a sample, apply an attribute sampling plan rather than an eyeball. ISO 2859-1 is the standard most third-party inspectors will work to, and agreeing an AQL level in writing before the inspection is what stops a good inspection and a bad inspection from producing different verdicts.
Alibaba's Trade Assurance terms, which Ruibit's listing carries, cover product quality and on-time shipment. Understand that as a floor rather than a substitute for your own inspection. The platform protects the transaction. It does not tell you whether the skimmer clears the chamber wall.
One order I got wrong
A composite pattern rather than a single account, and I still wince at it.
I ordered the top of the range for a client who wanted a visible feature piece, working from the litre figure and the product photograph. The cabinet alcove had been drawn by the client's own contractor, and nobody in the chain had converted the alcove drawing and the tank footprint into the same units on the same page.
The tank arrived, the alcove was fourteen millimetres short on depth, and the honest options were a rebuild of the alcove or a return. We rebuilt the alcove, at the client's expense and my embarrassment, because I had signed off a footprint I had never actually received in writing.
What changed afterwards was small and cheap. Every enquiry now gets a one-page dimension sheet before a quotation, and I ask for the same sheet signed back from the client. It takes twenty minutes and it has not gone wrong since.
FAQ
How do I know which model number maps to which volume?
Ask for the dimensioned drawing per model. In this range the published band is 28 to 72 litres covering the whole ladder from HB300 up to HB600S, and the per-model split is not stated in the listing.
Is the protein skimmer really included?
The listing names it as part of the set, along with the tank body, LED lamp, silent water pump and filter media. Confirm the model and rating of the included skimmer in writing, because an included skimmer that is undersized for the volume is not much of an inclusion.
Can I order a single unit to test before committing?
Minimum order on this listing is one piece, with a seven-day lead time quoted for quantities up to twenty. That combination is unusual at this price band and it is the cheapest way to run your own inspection before a container commitment.
Why does the listing quote one carton size for the whole range?
That is exactly the question to put to the supplier. A single 50 × 50 × 50 cm carton at 30 kg gross across a 28 to 72 litre band is either a figure for one model or a figure that needs re-checking.
What should I have in stock alongside the kit?
Spare impellers for the pump, a spare skimmer cup, and a set of media. In this category the part that fails is the moving part, and a two-dollar impeller arriving late costs you a customer relationship that a whole tank sale cannot buy back.
