Internal Filter vs Hang-on External: Which Is Better?
By AllPetSolutions | Published: 2026-10-26
Category: Comparisons
Compare the AllPondSolutions 700IF+ internal filter with UV and the 500L/H hang-on external filter. Learn which suits your tank size, water quality needs, and setup preferences.
Quick answer
For tanks up to 90 liters where easy installation and surface oxygenation matter, choose the hang-on external. For tanks up to 150 liters with persistent green water or disease risks, the internal filter with UV is the better choice.
Why UV matters for water clarity
Foam alone cannot remove the free-swimming organisms that cause green water and many fish diseases. The AllPondSolutions 700IF+ internal filter tackles this by building a 9W UV sterilizer into the filter body, killing algae, bacteria, and parasites as water passes through. The hang-on external lacks UV, so it relies entirely on mechanical and biological filtration.
Installation and tank fit
The hang-on external sits outside the tank, saving interior space and making it easy to access for cleaning. The internal filter sits fully submerged inside the aquarium, which can take up room but is simpler to set up in tanks without a rim or lid cutout. Both suit fresh or salt water, but the internal filter handles larger volumes (up to 150L vs 90L).
Trade-offs at a glance
- Filtration capacity: 700IF+ handles up to 150L; hang-on external handles up to 90L. Match filter to your tank volume to avoid under-filtering.
- Water quality control: 700IF+ includes UV sterilization for green water and pathogens; hang-on external relies on media only. If you struggle with algae or disease, UV is a clear advantage.
- Installation and space: Hang-on external mounts outside, saving interior space; internal filter sits in the tank, taking up room but requiring no external mounting. Consider your tank rim and available space before choosing.
- Oxygenation: Hang-on external's waterfall return adds oxygen naturally; the 700IF+ does not have this feature. For heavily stocked tanks, the hang-on may reduce the need for a separate air pump.
Key product differences
- AllPondSolutions 700L/H Aquarium Internal Filter with 9w UV 700IF+: Built-in 9W UV sterilizer kills algae, bacteria, micro-organisms and parasites as water passes through. This makes it effective against green water and disease-causing organisms that foam filters cannot remove.
AllPondSolutions 700L/H Aquarium Internal Filter with 9w UV 700IF+ - AllPondSolutions 500L/H Hang-on External Filter: Tumbling waterfall return oxygenates the water as it re-enters the tank. This adds dissolved oxygen without extra equipment, which benefits fish health in smaller aquariums.
AllPondSolutions 500L/H Hang-on External Filter
Which should you choose?
Best for
- Tanks up to 150L needing UV sterilization to combat green water or disease
- Aquarists who prioritize water clarity and pathogen control over interior space
Not ideal for
- Tanks under 90L where simple, space-saving installation and surface oxygenation are top priorities
