Aquarium silicone sealant that is actually for glass
Updated: 2026-10-23
You are sealing a fish tank or a vivarium, and the clear cartridge in the bathroom cupboard looks the same. Aquarium silicone sealant in this comparison means Bond It HA6, specified without fungicides or oils that might leach into the water. A sanitary anti-mould silicone is the easy mistake, because both stay transparent and both can smell of vinegar. The [Silicone clear comparison](/hub/fillers-adhesives-and-sprays/silicone-clear) holds the prices and stars from the amazon.co.uk snapshot of 19 October 2026. A qualifying purchase can earn us a commission at no extra cost to you.
You are sealing a fish tank or a vivarium, and the clear cartridge in the bathroom cupboard looks the same.
You are sealing a fish tank or a vivarium, and the clear cartridge in the bathroom cupboard looks the same. Aquarium silicone sealant in this comparison means Bond It HA6, specified without fungicides or oils that might leach into the water. A sanitary anti-mould silicone is the easy mistake, because both stay transparent and both can smell of vinegar. The Silicone clear comparison holds the prices and stars from the amazon.co.uk snapshot of 19 October 2026. A qualifying purchase can earn us a commission at no extra cost to you.
Our top picks
| Badge | Product | For tanks | Fungicide | Pack | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Bond It Bond It HA6 RTV silicone, clear, 3 pack | Yes, glass | None on the sheet | 3 × 310 ml | 9.6 | about £11.00 | View offer |
| Best value |  Bond It Bond It HA6 RTV silicone, clear | Yes, glass | Unanswered on listing | 1 cartridge | 9.4 | about £4.95 | View offer |
 Everbuild Everbuild general purpose silicone, clear | Sheet says no | Anti-fungal | 1; 260/280 ml | 9.2 | about £6.00 | View offer |
On this page
Aquarium silicone sealant is not bathroom silicone
The split is the fungicide, not the colour. Everbuild general-purpose clear, £6.00, states a fungicide, and the sheet says it is not for aquarium manufacture. Stay Clear says not for aquariums, and the safety sheet carries H412. HA6’s title says marine, aquarium and fish tank. The single cartridge is £4.95, 4.6 from 4,904 reviews. The three-pack is £11.00, 4.7 from 749 reviews, the top pick when you will use three tubes. The single cartridge is the best value for one tube. One review did not seal a plastic pond liner. A fungicide question on the single listing is unanswered. The technical sheet states that HA6 contains no fungicides or oils that might leach.
What Bond It actually says about HA6
Bond It’s aquarium note is guidance, not a guarantee, for tanks up to about 500 litres. It asks for toughened or laminated glass, about 6 or 8 mm at a water height of 30 cm and about 15 mm at 60 cm, a joint of about 1 mm, and a larger fillet on a bigger tank. Do not move the assembly until it has cured. The sheet classes HA6 as F EXT-INT and G 25LM to EN 15651-1 and EN 15651-2, not the sanitary part EN 15651-3. Skin is about 10 to 20 minutes, tooling about 5 to 10 minutes, and depth about 3 mm a day. Coverage is about 10 metres of a 6 mm bead from 310 ml. The three-pack states 310 ml and a unit count of 930 ml. The single listing does not state a volume. HA6 is not a mould-resistant bath sealant. A shower reseal belongs on the bathroom page.
Cure, rinse, and pH before any fish
Acetoxy silicone releases acetic acid while it cures, which is why the tank is rinsed before it is stocked. Bond It’s note says to rinse, check the pH, and test the assembly before animals go in. The note also says about one day per millimetre of glass thickness before you move the tank. A 10 mm wall is in the region of ten days on that wording. The listing’s 24-hour full cure and 2-minute initial hardening are cartridge figures. They are not a reason to fill a structural joint the next morning. Do not copy EVO-STIK 1 Hour’s shower claim onto a tank, and do not treat a 24-hour shower wait as the fill time. A 120 litre repair still needs that cure and a rinse. If the tank is beyond about 500 litres, or the glass is cracked, stop.
Names that are not this cartridge
UK searches also return Silirub AQ, AquaMate, Geocel Aquaria and Penosil. Silirub AQ’s sheet says it contains no toxins for fish such as fungicide, and that it must be fully cured and rinsed. It is not the Soudal in this table. These Soudal rows are Trade Multi-Purpose. The three-pack is £12.31 with eight reviews, and two buyers say the photo shows four tubes. The £12.95 title says six and weighs 310 g. AquaMate is what Everbuild names when it rules general purpose out of aquarium manufacture, and it is outside this set. Forum notes that name HA6 do not replace the Bond It note. Other jobs in this set are on the best clear silicone page.
Common questions
What aquarium silicone sealant is actually in this comparison?
Bond It HA6 clear. One cartridge is £4.95, 4.6 from 4,904 reviews, the best value for a single tube. The three-pack is £11.00, 4.7 from 749 reviews, the top pick when you need three. The sheet says no fungicides or oils that might leach. The other cartridges here exclude aquarium use.
Can you use clear bathroom silicone in a fish tank?
No. Fungicidal bathroom silicone and fungicide-free marine silicone are different products even when both look clear. Stay Clear says not for aquariums and not for submersion. Everbuild general purpose says not for aquarium manufacture. The one-hour shower listing is a bathroom product. Colour is not a safety test.
Does marine or clear on the title mean fungicide-free?
Clear means the colour. Marine on the HA6 title is the claim you then check against the Bond It sheet, which is where the absence of fungicide is stated. A fungicide question on the amazon.co.uk listing is unanswered. Do not treat the word marine on some other clear cartridge as the same statement.
How big a tank does Bond It say HA6 is for?
The note is guidance, not a guarantee, for tanks up to about 500 litres. It asks for toughened or laminated glass, thicker as the water gets deeper, a joint of about 1 mm, and a larger fillet on a bigger tank. A strong review is not a reason to build past that size.
How long do you wait before you fill the tank?
The HA6 note says about one day per millimetre of glass thickness before you move the tank, and to respect that cure before filling. Rinse because an acetoxy silicone releases acetic acid, check the pH, and test the assembly before you add fish.
Is the Soudal clear silicone in this table the aquarium grade?
No. Silirub AQ is Soudal’s aquarium silicone, and it is not one of these ASINs. The Soudal rows here are Trade Multi-Purpose. A photo that shows four tubes, or a title that says six while the weight is 310 g, does not make the chemistry fish-safe.
Related pages
Sources
Public UK sources used for this comparison. amazon.co.uk prices, stars and review counts were taken from the listings on 19 October 2026.
- Everbuild General Purpose Silicone product data sheet (retrieved 19 October 2026)
- UKCA declaration BS EN 15651-1, Everbuild general purpose silicone (retrieved 19 October 2026)
- Bond It HA6 technical data sheet (retrieved 19 October 2026)
- Bond It HA6 aquarium guidance (retrieved 19 October 2026)
- EVO-STIK Stay Clear sanitary silicone technical data sheet (retrieved 19 October 2026)
- EVO-STIK Stay Clear product page (retrieved 19 October 2026)
- Soudal Trade Multi-Purpose Silicone technical data sheet (retrieved 19 October 2026)
- Approved Document F, ventilation (retrieved 19 October 2026)