Decision essentials
Key points
Most filter pumps do not self-pump air.
An air leak prevents stable prime.
Tilt or shake only when instructed.
Filtration
Before power
Check tank level, seal, lid, valves, hose and submerged intake. Pre-fill HOB or vessel where required.
Never mouth-siphon aquarium water; use the equipment’s safe method.
Filtration
After initial return
Air noise should decline. If cavitation persists, stop and find the entry rather than waiting minutes.
Verify leaks, flow and short outage restart; keep the procedure nearby.
From evidence to action
Decision matrix
| Situation | What to do | Why |
|---|---|---|
| Motor hums dry | Disconnect immediately | Prevents heat damage |
| Bubbles persist | Find air-side leak | Circuit is not closed |
| Prime lost while off | Inspect valves and level | Air enters or water drains |
Check the result
After the adjustment, measure flow under the same conditions and check noise, leaks, waste accumulation and circulation. Record the result; if performance drops again, locate the restriction before changing another part of the system. For “Prime and restart a filter without running the pump dry”, use tilt or shake only when instructed as the final article-specific check.
Evidence
Sources and scope
Sources include institutions, technical studies and manufacturers. Chezur separates established mechanisms from editorial decisions for home aquariums.
- EHEIM — External filter operating manual manufacturer
- FAO — Pipe head loss in aquaculture design institution