Quick answer: You can still change the design after the drawing is approved, but the cost and delay depend entirely on where the factory is in the build cycle. Changes requested before glass cutting are usually free or cheap; changes after the glass is cut cost 20–50% of the affected panel; changes after the tank is bonded can mean starting over. The rule is simple: ask early, ask in writing, and expect a revised lead time.
The Three Stages That Determine the Cost
Custom aquarium manufacturing moves fast once the deposit lands. A 200 cm reef tank goes from approved drawing to water test in about 25–35 working days. Your change request hits very different costs depending on which of three stages the factory has reached.
| Stage | What has happened | Change cost | Lead time impact |
|---|---|---|---|
| Before material cut | Drawing approved, glass ordered | Free to +$50 admin | 0–2 days |
| Glass cut, not yet bonded | Panels cut, waiting for silicone | 20–40% of affected panel | 3–7 days |
| After bonding and water test | Tank is glued, tested, near packing | 50–100% of unit cost; may need rebuild | 10–20 days |
Most buyers do not realise that the moment the glass hits the cutting table, the cost of a size change stops being a drawing exercise. A single pane of 12 mm low-iron glass cut to 2000 × 600 mm cannot be re-melted. If you want it 1900 mm long, that panel becomes scrap.
Common Change Requests and What They Actually Cost
The table below covers the five changes most often requested after sign-off, and what each one typically triggers.
| Change request | Typical cost | Lead time | Notes |
|---|---|---|---|
| Move a logo position | $0–30 | 0 days | Before silk-screening; ask in writing |
| Change cabinet color | $50–120 | +2 days | If laminate not yet applied |
| Add an overflow box | $120–300 | +5 days | Requires new glass panel |
| Increase glass thickness | $180–400 | +7 days | All panels re-cut, not just one |
| Change overall tank length | $300–800 | +10–15 days | Entire glass order scrapped |
A change that looks cosmetic on the drawing — moving the overflow by 10 cm — can cascade into a new glass cut, a new sump plumbing run, and a revised cabinet. The factory's job is to flag that cascade, not just say "yes."
How to Request a Change Without Causing Chaos
Three habits keep change orders cheap:
- Send a marked-up drawing, not an email. A screenshot with a red circle is faster to act on than a paragraph. The factory engineering team quotes from drawings, not from prose.
- Ask for a revised lead time in the same email. Do not ask "can we move the outlet 5 cm?" and wait. Ask "can we move the outlet 5 cm, and what is the new ship date?" The answer tells you whether the change is still free.
- Do not change scope in the same call as a payment. Mixing a design change with a balance payment creates paperwork disputes. Pay against the original approved drawing, then process the change as a separate variation order.
A Worked Example
A hotel specifier approved a 240 cm reef tank drawing in May, then two weeks later decided to move the viewing window from the front to the side to suit a new lobby plan. The factory had not yet cut glass, because the deposit was still clearing. The change was processed as a revised drawing, signed off again within 48 hours, and the lead time moved by only one day. The same request, made ten days later when the glass was already on the cutting table, would have cost about $450 in scrap panels and delayed the order by a week.
Ruibit keeps the drawing approval stage as a two-way checkpoint: the factory sends a PDF with dimensions, material, and bracing, and the buyer signs off before glass is ordered. If you need to change something, reply on that drawing with a mark-up, not a verbal call to sales.
What to Ask Before You Sign the Next Drawing
Three questions turn the approval step into a safety net:
- How long after drawing approval can I request a change without affecting lead time?
- What is the cost threshold above which a change becomes a separate purchase order?
- If I need to change something after glass is cut, can you quote the scrap cost before proceeding?
Send the approved drawing back with your mark-up and the target install date, and we will confirm in writing whether the change is free, carries a line cost, or requires a rebuild — before the glass hits the table.
FAQs
Can I change a custom aquarium after the drawing is approved? Yes, but cost depends on the build stage. Before glass cutting, changes are usually free. After cutting, expect 20–40% of the affected panel. After bonding, it may require a rebuild.
What changes are free after sign-off? Logo position, cabinet color before lamination, and minor plumbing adjustments are typically free if requested before material cutting. Send a marked-up drawing, not prose.
How much does increasing glass thickness cost? $180–400 plus 7 extra days, because all panels are re-cut, not just the changed one.
How do I request a change without delays? Send a marked-up drawing, ask for a revised lead time in the same email, and do not mix design changes with balance payments.
What should I ask before signing the next drawing? How long changes stay free, the cost threshold for a separate PO, and whether the factory quotes scrap cost before proceeding.
