Seachem® Paraguard™ Parasite Control Solution
ParaGuard™ is the only fish and filter-safe aldehyde-based parasite control product available for treating ectoparasites on fish. Formulated with 10% aldehyde by weight, it contains no formaldehyde or methanol, making it safer for both fish and aquatic environments. Unlike formalin-based treatments, ParaGuard™ does not alter water pH and is compatible with filters and aquarium systems.
It features a proprietary blend of aldehydes, malachite green, and fish-protective polymers to effectively treat a range of external parasites such as ich, as well as fungal, bacterial, and viral lesions including fin rot.
Recommended for use in hospital tanks, receiving tanks for new fish, or when introducing new fish to a community tank.
Product Specifications
| Component | Value |
|---|---|
| Active Ingredient | 10% aldehyde by weight |
| Contains Formaldehyde | No |
| Contains Methanol | No |
| Water pH Impact | None |
| Safe for Filters | Yes |
| Safe for Fish | Yes |
WARNING: Do not ingest, drink, or come into contact with eyes. In case of eye exposure, rinse thoroughly with water and seek medical attention immediately.
FAQ
Can ParaGuard™ be used in a community tank with established fish?
Yes, ParaGuard™ can be used in a community tank, especially when introducing new fish or treating external parasites like ich or fin rot. It is safe for fish and compatible with filter systems.
Does ParaGuard™ affect water pH levels?
No, ParaGuard™ does not alter water pH levels, making it suitable for use in sensitive aquarium environments.
Is ParaGuard™ safe for use in hospital tanks?
Yes, ParaGuard™ is particularly effective in hospital tanks for new fish, helping to prevent the spread of parasites and infections during acclimation.

Faith Graham –
Used ParaGuard™ when introducing new fish to my tank. No pH changes, fish stayed healthy, and ich was completely gone within a week. Easy to mix and safe for filter use. Highly recommended for new fish introductions.
Keith Arnold –
Tried it after a fin rot outbreak. The treatment worked well without harming my fish or altering water chemistry. The instructions were clear and the product was effective in reducing bacterial lesions.
Piers Robertson –
Great product for treating external parasites. No formaldehyde means less risk to fish and equipment. Works quickly and doesn’t stress the fish like other treatments do.