Here's some information on why using a foam layer under your aquarium can be beneficial: 

1. Even Weight Distribution

• Aquariums can be very heavy, especially once filled with water, substrate, and decorations. Without a foam layer, small imperfections or unevenness in the surface underneath the tank can cause concentrated pressure on certain areas of the glass. Over time, this stress can lead to cracks or even a tank failure.
• The foam layer acts as a cushion, filling in any minor gaps or unevenness between the tank’s base and the surface it sits on, ensuring that the weight is evenly distributed.

2. Protection Against Imperfections

• Even the most meticulously level cabinets can have small imperfections, such as slight bumps or uneven spots. These imperfections might not be visible to the naked eye but can still cause undue stress on the aquarium’s glass, leading to potential damage.
• The foam layer can help absorb these imperfections, providing a more stable, secure base for the tank and preventing long-term pressure build-up in one area of the glass.

3. Shock Absorption

• Aquariums are sensitive to impacts or vibrations. A foam layer can provide a level of shock absorption, protecting the glass from sudden impacts or movement (whether from the environment or accidental bumps). This can help prevent cracks or damage from external forces.

4. Level Surface

• It is crucial for the tank to sit on a perfectly level surface. An uneven surface, even by a small amount, can cause pressure on one side of the tank. Over time, this uneven stress may result in distortion or even failure.
• While many aquarium stands are designed to be level, using a foam layer can help further ensure the tank sits securely on a perfectly flat surface.

5. Better Long-Term Stability

• In addition to helping with weight distribution, a foam layer can add an extra layer of protection to ensure that the aquarium remains stable for many years. It also provides some flexibility, ensuring that minor shifts in temperature or humidity won’t affect the stability of the aquarium setup.

Should You Always Use Foam?

• Not all aquariums require a foam layer. As mentioned, it is not standard for our aquariums to include a foam layer. If your aquarium is placed on a solid, flat, level surface (like the included cabinet), and the tank itself is properly sized for the cabinet, you might not need a foam layer.
• However, for larger tanks or if you’re placing your tank on a less-than-ideal surface (like an uneven or old cabinet), the foam layer could provide additional reassurance and protection for your aquarium.

Conclusion

While a foam layer isn’t always necessary, it can be a useful precautionary measure for certain situations, especially for larger tanks or those placed on surfaces that may not be perfectly level. Always ensure your aquarium sits on a flat, stable surface, and follow the manufacturer's recommendations for optimal setup.