A common question that pops up in our enquiry forms and inboxes is whether surface or sub-surface aeration is better. While we’d love to give you a simple answer, there really is no one size fits all cure. While both kinds are excellent, the best kind of aerator for you pond depends on factors such as shape, depth, power location and your goals. We’ve put together this handy guide to help you find the perfect solution for your pond or dam, but if you’re still unsure by the end of this article, feel free to contact us any time for expert advice and assistance.

Why do I need aeration?

Aeration is possibly the most important aspect of caring for your water body. Every part of your ecosystem, from your tiny bacterial helpers to your plants and biggest fishy friends, need oxygen to survive and thrive. You may think you’ll be ok with your top quality filter and pump but even the best filtration system will generally struggle to keep your aquatic ecosystem in peak condition if there isn’t enough oxygen in the water.

Note that while plants can help with oxygenating your water during the day, they consume it at night so you’ll still need a way to maintain balance even in a well vegetated pond. Waterfalls and decorative fountains can also assist in aerating your pond, and improving the aesthetics of your little environment, but they simply cannot provide enough oxygen to improve your water quality in nine out of ten cases.

Benefits of Surface Aeration

Surface aerators are generally better for shallower ponds designed in basic shapes. By this we mean that if one or two units can effectively maintain contact with the entire water volume, a floating fountain or other surface option can be a great fit for your pond.

Some of the benefits of surface aeration include:

  • They can create a nice ‘fountain’ display.
  • Surface aerators can be operated at really shallow depths.
  • They are also suitable for depths up to 2m deep allowing for great flexibility.
  • They are generally super easy to install.
  • As this type of system does not require you to have power in the water, surface aerators are great for those who want to swim in their waterbody.

Note: Surface aeration systems require some maintenance to ensure that the propeller is kept free of algae, weeds, etc.

If you’re looking to add a little wow factor, check out Our Quick Start Guide To Fancy Fountain Features.

Benefits of Sub-Surface Aeration

Sub-surface aerators involve an air compressor pushing air through hose, into diffusers (or airstones) and up through the water column. These systems are great for deeper systems and where the shape of the pond tends to be more irregular. While they do not create as much of a water feature as the surface variety does, they tend to offer better aeration for larger water bodies and some may even consider their minimal visual effect to be a good thing.

Some of the benefits of sub-surface aeration include:

  • Because there are so many sizing options, it is easy to find a sub-surface aerator to fit almost any pond.
  • Sub-surface systems do not require the use of power in the water. In fact, you don’t even have to have your power supply by the edge of your pond.
  • They are really easy to maintain, simply clear the filter element every 3 months and apply a re-build kit after 2-3 years.
  • They can be powered by mains electricity, solar power or by utilising wind and airflow.
  • You can start your system small and add to it later if required.
  •  One compressor can run multiple diffusers so sub-surface is a more cost effective system for long, narrow, unusual shaped systems.

If you’re working out what kind of aeration to install, hopefully this guide has answered all of your questions but if you’d like some more specific information or personalised advice, get in touch and we’ll help work out the best solution for your water body. Remember that both types provide vital oxygen to your aquatic ecosystem, so there’s no need to stress out and remove your current system if you feel it isn’t exactly right for your water body. Our friendly specialists are just as happy to help with existing set ups as they are assisting beginners so if you’re unsure of anything drop us a line and we’ll help you out.