Which One Is Better: No Lid or Lid on an Aquarium?
This topic of lidded (closed-top) vs no lid (open-top) aquariums is one of the more divisive topics, aside from that of reef keeping vs. fish keeping, within the aquarium hobby. There is a lot to consider between the two versions and both offer their own pros and cons which can heavily influence your hobbyist journey, how you maintain your aquarium, and the health of the fish that live in it.
In this article, we will take a look at some of the important factors to help you decide which of the two approaches is better for you in regard to your setup and preferences.
Why Are Aquarium Lids Good?
Safety and Containment
The most common reason for adding a lid to an aquarium is escape prevention. A wide variety of fish species, especially jumpers such as wrasse, tangs, and some species of gobies are known to jump out of tanks when stressed or in feeding frenzies. Knowing that a secure lid is the first line of safety from the tragic loss of beloved specimens brings peace of mind.
Beyond fish, some invertebrates need to be considered too. Flying squid and some crab species are masters at escaping and capable of climbing up rocks and on aquarium equipment, and escaping from saltwater tanks. So, if your saltwater aquarium contains these creatures, a lid would be a necessary piece of containment.
Evaporation Control
Evaporation is a common occurrence in aquariums, and it needs to be maintained. Open-top aquarium systems tend to lose a lot more water than closed-top aquariums. It is estimated that a mid-sized aquarium (around 40 gallons) will lose ½ to 1 inch of water every day under normal household conditions. This evaporation:
-
Adjusts dissolved solutes, which can impact the aquarium water chemistry.
-
Requires consistent top-off to uphold steady conditions.
-
Develops salt creep in marine aquariums as salt is left behind when water evaporates.
-
Elevates humidity in neighboring areas and affects viewport damage to walls, ceilings, and surrounding furniture.
Aquarium Lids Protect Against External Contaminants
Open-top aquariums are more susceptible to foreign elements than closed-top aquariums. Common contaminants that can enter open-top aquariums include the following:
-
Dust and airborne particles that can clog water and possibly add pollutants
-
Household chemicals from cleaning products, air fresheners, and sprays
-
Objects that get accidentally dropped into the tank
-
Large inquisitive pets that may consider your fish tank an all you can eat buffet
If your household has children, pets, or regular use of aerosols, you will benefit from the additional protection lids provide against accidental contamination.
Temperature Stability
Covered aquariums are generally better insulated and therefore temperature fluctuations are less drastic, especially in location where the surrounding environment gets heated or cooled, e.g. an air-conditioned or heated room. Such thermal stability helps alleviate stress on inhabitants and could lessen heater energy usage in colder climates.
Benefits Of Open-Top Aquariums
Aesthetic Appeal
-
More light penetrates the water for improved visibility and appearance.
-
They blend into the surrounding decor better.
-
They allow aquascapes to break the waterline and create more dynamic compositions.
Light and Plant Growth
-
Open-top aquariums have no light diffusion or spectrum shift from plastic or glass covers.
-
You can install non-permanent hanging pendant lighting at adjustable heights when there is no lid.
-
Open-top aquariums allow increased light penetration, which enhances plant growth.
-
If you have plants that require emergent access such as pothos, peace lilies, or more specialty paludarium plants, open-top aquariums are better.
FUN FACT: In open-top aquariums, plants receive 10-15% more usable light than in tanks with normal lids/hoods or glass covers.
Gas Exchange Benefits
Open-top aquarium designs facilitate better gas exchange at the water surface. Open-top systems:
-
Improved oxygen solubility - this is very useful if your aquarium is well-stocked.
-
More efficient carbon dioxide (CO2) in planted tanks with no need to supplement CO2.
-
Enhanced dispersion of possibly toxic gasses from substrate breakdown.
Maintenance Accessibility
Maintenance becomes easier without lids to remove and replace:
-
Functions with free-movement parts make feeding corals easy.
-
Faster water testing and treatment input.
-
Easier water changes, sand cleaning, and gravel vacuuming.
-
Easier plant trimming and aquascaping adjustments.
A Middle Ground - Hybrid Aquarium Cover Approaches
Most aquarium hobbyists take hybrid approaches that combine the advantages of both aquariums with lids and without lids.
-
Partial Covers: These covers leave space at the top of the tank, making it easier for feeding and maintenance.
-
Mesh Screens: These keep jumpers out but allow gas exchange and light to penetrate.
-
Custom-Cut Glass Lids: These have cutouts for installing equipment and feeding livestock.
-
Floating Flora: Adding floating plants to aquariums can increase oxygen levels and water quality whilst also deterring jumpers.
Is An Open- or Closed-Top Aquarium Better?
If you’re weighing lidded versus open-top designs, you should consider:
1. Habitants: If you want any jumping/climbing species, you will need a secure cover.
2. Room environment: Humidity tolerances, dust amount, and temperature stability.
3. Other household members: Include risk factors from children (like not washing their hands), cats, or chemicals used around the house.
4. Maintenance needs: Cut your water top-off frequency, but clean much more often.
6. Plant restrictions: If you have plants, pay attention to light requirements.
Conclusion
There is no one-size-fits-all answer as to whether a lidded aquarium or an open aquarium is better. Instead of seeing this as a binary choice, think about what elements of both approaches will best help achieve your aquarium goals, and be willing to get creative if that means hybridizing solutions.
The best aquarium is the one that meets the needs of the organisms within its controlled environment while also meeting your ability to maintain its upkeep and the aesthetics you want.
Don’t know where to start? At Reefco Aquariums we can help with every step of your hobbyist journey - from designing and installation to service and maintenance needs. Contact the Reefco Aquariums team to book your consultation today.
