Evidence decisions
Reading an aquarium-treatment safety data sheet
Use an SDS to check identity, hazards and revision details. Keep those findings separate from the manufacturer’s instructions about aquarium livestock.
Formulation evidence record
Seachem ParaGuard
External parasite and fungal treatment · US formulation
Shrimp
Amano, cherry, crystal and other freshwater shrimp.
Snails
Nerite, mystery, ramshorn and other aquarium snails.
Live plants
Rooted and floating live aquarium plants.
Scaleless fish
Loaches, corydoras, plecos, eels and other scaleless species.
Marine invertebrates
Corals, anemones, starfish and marine crustaceans.
Not addressed by the manufacturer for: biological filter. No statement was found, so no verdict is given — that is not a clearance.
Why FishyMag says this
The manufacturer's own wording, quoted rather than paraphrased, so you can judge it yourself.
Shrimp
Manufacturer advises againstSeachem's Directions open by instructing keepers to remove all invertebrates before dosing. Their FAQ is softer — they decline to certify the product as invert safe rather than forbidding it — but an instruction in the Directions outranks a hedge in the FAQ, so this is recorded as advise-against.
Contains aldehydes, with a source-linked caution associated with this group. This raises a flag—it is not the basis of the verdict above.
“Remove all invertebrates from the tank as well as any chemical filtration”
manufacturer page · seachem.com · checked August 16, 2026
“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
Snails
Manufacturer advises againstSnails are invertebrates and fall under the same opening instruction in the Directions to remove all invertebrates before dosing.
Contains aldehydes, with a source-linked caution associated with this group. This raises a flag—it is not the basis of the verdict above.
“Remove all invertebrates from the tank as well as any chemical filtration”
manufacturer page · seachem.com · checked August 16, 2026
“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
Live plants
CautionSeachem describes it as generally safe in planted aquaria, but frames this as their experience rather than a tested guarantee. That is weaker than a label claim, so it is recorded as caution rather than compatible.
“generally safe to use in planted aquaria”
manufacturer faq · seachem.com · checked August 16, 2026
Scaleless fish
CautionPermitted, with an explicit instruction to start low. Seachem says scaleless species can be more sensitive and recommends beginning at a quarter to half dose before building up.
Contains malachite green, with a source-linked caution associated with this group. This raises a flag—it is not the basis of the verdict above.
“You can use any of our medications with scaleless fish, but as they can be more sensitive, we would recommend that you begin with a 1/4 to 1/2 dose first and slowly build to the recommended dosage.”
manufacturer faq · seachem.com · checked August 16, 2026
Marine invertebrates
Manufacturer advises againstSeachem states plainly that ParaGuard is not recommended for reef aquaria, alongside the Directions instruction to remove all invertebrates.
Contains aldehydes, with a source-linked caution associated with this group. This raises a flag—it is not the basis of the verdict above.
“Remove all invertebrates from the tank as well as any chemical filtration”
manufacturer page · seachem.com · checked August 16, 2026
“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
Check the evidence boundary
What this record can—and cannot—answer
Bottle identity
US formulation · label revision: not recorded · version: not recorded.
Match the label and concentration on your bottle before using a dose ratio.
Unresolved groups
Biological filter
Missing evidence is not a compatibility finding.
Product combinations
No specific interaction warning is recorded here. This is not a complete interaction review or permission to combine treatments.
Evidence age
Formulation record checked August 16, 2026. Source dates can differ within the record. A dated check is not a guarantee that the label has stayed unchanged.
Product details
- Manufacturer states it treats
- External parasites, Fungal infections, Bacterial and viral lesions
- Chemical filtration
- Remove chemical filtration during treatment
- Ingredients as stated
- A proprietary, synergistic blend of aldehydes, malachite green and fish protective polymers (10% aldehydes by weight).
- Active ingredients
- AldehydesMalachite green
manufacturer page · seachem.com · checked August 16, 2026
Record last checked August 16, 2026 · confidence high
Check against your tank
Change what is in your tank to see how the answer moves.
The biological filter is included in every non-empty tank check, alongside your selected groups.
External parasite and fungal treatment · US formulation
The manufacturer advises against using this with your tank.
At least one selected group is named in a warning. Read the exact instruction and ask the manufacturer to clarify your setup before dosing.
This answers for the assumed selection above, not a tank you have described. Adjust it if it is not yours.
- ShrimpManufacturer advises against
Seachem's Directions open by instructing keepers to remove all invertebrates before dosing. Their FAQ is softer — they decline to certify the product as invert safe rather than forbidding it — but an instruction in the Directions outranks a hedge in the FAQ, so this is recorded as advise-against.
- SnailsManufacturer advises against
Snails are invertebrates and fall under the same opening instruction in the Directions to remove all invertebrates before dosing.
- Live plantsCaution
Seachem describes it as generally safe in planted aquaria, but frames this as their experience rather than a tested guarantee. That is weaker than a label claim, so it is recorded as caution rather than compatible.
- Biological filterNo evidence found
No statement from the manufacturer was found for this group. Treat it as unconfirmed and check with the manufacturer before dosing.
See the manufacturer’s exact wording and sources for Seachem ParaGuard →
No evidence found means no manufacturer statement was found — not that the product is safe. FishyMag does not diagnose disease or recommend treatments.
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Understand the label in context
Label case studies
Is ParaGuard safe for shrimp and snails? Read the removal instruction
Seachem’s ParaGuard directions tell users to remove invertebrates. Learn why a copper-free claim and a qualified FAQ do not override that instruction.
Next steps
Does this record match your bottle?Compare the name, market and label details. Download unresolved identity questions.Resolve an unanswered question about Seachem ParaGuardDownload the evidence and a manufacturer enquiry with your bottle details and livestock groups.Keep a treatment recordRecord what was actually used and when. Save on this device or export for a support conversation.How much Seachem ParaGuard for my tank?Scales the label ratio to your real water volume, with the manufacturer wording beside the answer.Check against my tankSee how Seachem ParaGuard and every other treatment compare against what you actually keep.Compare with another treatmentPut Seachem ParaGuard beside up to three alternatives, group by group.Work out your real water volumeDose against the water your tank holds, not the number on the box.
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.