Ingredient risk record
Aldehydes
Also appears as: glutaraldehyde, formaldehyde, formalin
ParaGuard lists aldehydes and its manufacturer declines to market that formulation as invertebrate safe. FishyMag carries that formulation-level uncertainty forward as a caution signal, not as a claim that every aldehyde formulation has the same compatibility profile.
Source-linked caution for
The evidence is formulation associated. It raises a warning on a product containing this ingredient but never decides the verdict.
“We do not sell or market ParaGuard™ as invert safe because it would be impossible to test it with every available invert under every potential water parameter.”
manufacturer faq · seachem.com · checked August 16, 2026
The inference only runs one way
A product containing aldehydes gets a warning. But a product without it gets nothing — no clearance, no green tick. Fritz Algae Clean Out contains no copper and is still explicitly unsafe for shrimp and snails, which is why FishyMag will not certify a product as compatible unless the manufacturer says so directly.
Treatments containing aldehydes
Next steps
FishyMag reports what manufacturers say, quoted and linked. It does not diagnose illness or recommend a treatment, and it never infers that a product is safe from the absence of a warning — where no statement exists, it says so.
Formulations change. Always read the label on the bottle in your hand, and contact the manufacturer if your tank contains anything valuable or unusual.