Should I use acidic silicone sealant or neutral silicone sealant for my aquarium?

 

In aquariums (especially for glass bonding and sealing in direct contact with water), neutral silicone sealant must be used, specifically labeled for aquariums/fish tanks.

The reasons are as follows:

Acidic silicone sealant:

Releases acetic acid: During the curing process, acetic acid (ethanoic acid) with a strong, pungent odor is released. This acidic gas:

Highly toxic to aquatic life: Can cause serious harm or even death to fish, invertebrates, and beneficial bacteria.

Corrosive to metal: Can corrode metal parts in aquariums (such as heater housings, pump shafts, and lighting fixtures).

Residual odor: Even after curing, a residual odor may remain, affecting water quality and inhabitants.

Unsuitable for long-term submersion in water: While it has some adhesion, its long-term water resistance and aging resistance are generally inferior to those of high-quality neutral aquarium sealants.

Potential additive risks: May contain additives harmful to aquatic life (such as mildew inhibitors).

Neutral Silicone Sealant:

Alcohol Release: Alcohols (such as methanol and ethanol) are released during the curing process, resulting in a relatively mild odor.

Relatively Biosafe: The released alcohols evaporate quickly and are much less toxic to aquatic life than acetic acid. However, this applies only to types specifically designed for aquariums.

Excellent Water Resistance: Glues designed specifically for aquariums offer excellent long-term water immersion resistance and bond strength, capable of withstanding significant water pressure.

Excellent Elasticity: They can adapt to minor deformations of glass caused by temperature fluctuations and water pressure, preventing leaks.

No Harmful Additives: Key Point! Neutral silicone sealants specifically designed for aquariums strictly control or avoid the use of additives harmful to aquatic life (such as certain types of mildew inhibitors) during production. Ordinary neutral glass glue/construction sealants may contain these harmful substances.