Normal Silicone Vs Aquarium Grade Silicone

[Neo8223]

Ok, Its a known fact that using normal silicone is bad as it leaks out "bad stuff" into the aquarium. However, as this is a DIY page and loads of people keep normal silicone sealent at home, i was wandering, how long it takes for the silicone to become safe, if at all, using just normal filters and the simple aquarium setup.

(Lets face it, anyone who has a RO unit isnt gonna cut corners with silicone )

 

[doresy]

Personally, I think that like most things, if it's in a small amount it allows for the price to be sky high. I have used ordinary, low modular silicone with absalutely no problems. Other's, of course, may disagree but are they just following the crowd or is there justification??

 

[Rooster]

PURE silicon sealant is just that, even if it carries the word AQUARIUM or not ! A lot of folk on here will maintain that they only buy from pet/fish shops "to be on the safe side" purely out of ignorance I suspect.
There are LOADS of stuff that is safe for use, key words are "food safe" ... superglue is safe, the list goes on.

Regarding sealant, you MUST ensure its pure and contains NO anti-fungal agents etc.









Engage tin hat ! lol

 

[Lateral Line]

The usual problem is determining if it does contain fungicide or not. As the OP points out, if you are going to spend a fortune on your fish etc., why save a small amount on your sealant. I can buy "Aquarium safe" badged sealant for more or less the same price as the bathroom or building sealants in the DIY superstore.

 

[Rooster]

If it contains fungicides, it will SAY SO... and a quick search reveals:

AQUARIUM stuff

Non aquatic branded

Which show it is at least half the price of "proper" stuff... at least in the UK, no doubt a little digging will find an even cheaper source.
Considerable savings can be made by shopping "wisely" especially if you are building a new tank...

 

[Neo8223]

So the conclusion: If you want to use silicone, do not cut corners and use that little bit of spare silicone you have in the garage. Go to a DIY store, or go online to find aquarium safe silicone. This is identified by stating aqwuarium safe silicone, OR having any fungal agents etc etc. It MUST BE PURE SILICONE. Its not worth risking to loose all of your fish and contaminating your aquarium for the sake of a few quid... This is just false economy cuz its gonna cost you more in fish.

Thanks to everyone who participated in helping me to answer the question.

 

[Lateral Line]

If it contains fungicides, it will SAY SO... and a quick search reveals:

Anyone can find sites on the net that say whatever, that does not translate into the experience in the shop where you have in front of you what they have. There will be good brands with lots of information and there will be cheap stuff imported from some out of the way place with the directions written in Serbo-Croat and the composition in Chinese.

Another issue with cheapo brands is that cheap stuff is usually bought in bulk as a spot commodity and packaged somewhere else. Two tubes of sealant of the same brand, particularly "budget brands", may have totally different pedigrees. Often made in places where the quality control is lacking.

You pays your money and you takes your choice.

 

[Rooster]

You pays your money and you takes your choice.

Of course you do... thats life, but this IS a DIY forum, you may as well say dont build a hood in case there are prevervatives in the wood, or best to buy your water from a fish shop... where IS the line ?

I suppose the golden answer is, if you are unsure then dont do it, but to be fair - dont ask for help in DIY either if you are uneasy with the responses you receive.
My local fish shops ALL buy from non aquarium suppliers for some stuff (substrate is a good example) which they then fleece the customers with.
I have been using this alternative stuff for 40 years without issue, its a matter of self confidence and research.

 

[Lateral Line]

One should equally advise not to expect everyone to have the same opinion or experience.

By the way, 40 years ago, I didn't have silicone sealant. When I built in the early '60's, it was angle iron and putty. Sealant, "leak stopper", was a heavy brownish yellow wax that you melted and poured over a leaking seam.

 

[Rooster]

One should equally advise not to expect everyone to have the same opinion or experience.

I dont... or didnt, thats why I try to help on the forum... pass on a little advice !

By the way, 40 years ago, I didn't have silicone sealant. When I built in the early '60's, it was angle iron and putty. Sealant, "leak stopper", was a heavy brownish yellow wax that you melted and poured over a leaking seam.

Dont remember the seal stopper... mine was green stuff, I got my dad to replace the dried out stuff as he was a builder, and I was a kid !

 

[Lateral Line]

Putty was green. A soft plasticene like material, had an odd linseed oil smell. If allowed to, it would dry out, crack and break up into small pieces. At that point, your seam would usually start to "weep", and if untreated would leak substantially. It never failed in the catastrophic manner silicone can sometimes do.

The leak stopper stuff was sold by "Hykro". You emptied the tank, cleaned the seam that was leaking with meths, then melted a block of this stuff. When fluid, you propped the tank at an appropriate angle and poured the stuff along the glass/glass join. It partially filled the crack, but more, stuck to the glass and formed a, (relatively), water tight seal again. Saved having to dig the old putty out and re-glazing the frame.

*** EDIT ***

The wax stuff had a "shoe polish" like smell I remembered later!

 

[Bowman]

The leak stopper stuff was sold by "Hykro".

Heheee, wot a good thread, wot a good read and oh the nostalgia !

When my first angle iron tank after several good years of use sprang a leak, about 42mumbley ago (since we are mentioning those things, years !) and a digs move, I repared it with something called "H,,," ( couldnt remember its name, when I first read this thread, till LL filled it in as Hykro) but mine was black, squeezed out of a tube ( a bit like model aircraft glues in those days that were sealed wirh a pin after)
It was quite useless in that it dried and became quite brittle and would at the first opportunity crack and then leak in the same place !

I soon became expert at 're-puttying' angle iron frames with, well putty of course !, which was not odd that it smelled of linseed oil, 'twas based upon linseed oil !!
In those bygone days it was easy to obtain orthophosphoric acid by the gallon, with which to de-rust ones angle iron first.
(actually it only converted red oxide to black oxide, but that is another story ,, pssst for extra points )
and sometimes, if the orthophosphoric was not flushed well enough the excess volume of the convertied rust/iron oxide would cause the newly reglazed tank to crack again because one had not used enough of a 'pad' of putty.

then melted a block of this stuff. When fluid, you propped the tank at an appropriate angle and poured the stuff along the glass/glass join. It partially filled the crack, but more, stuck to the glass and formed a, (relatively), water tight seal again.

Errr, you are not thinking of "pitch" by any chance ???

Saved having to dig the old putty out and re-glazing the frame.

Which was by far the best method, penny saved-pound-wasted was a catch phrase in those days

He ho, what fun we had !
But I'm with Rooster, I'm only in my hobbies to learn stuff, and you dont learn stuff just by buying the proprietary blend off of the aquarium retailers shelf.
Yes, it means risks, but that's a price of learning.

Thank G*d for silicone !
pssst, I've still got an angleiron 5ftx15x18 frame out there, any offers, just needs glass and putty ,,, ,, museums anyone ??

 

[raptorrex]

caravan and boat, shops suppliers all keep pure silicon, which is safe, and more often than not better quality than, so called aquarium sealant. it cost a fraction of the price, but this is not a result of cheap product,. just simply a result of the vast amount of sealant, sold and needed in that market. many many "aquarium safe" products are nothing more than over priced, and often lower quality, items aimed at a restricted market.

two eyes and a reasonable brain, will find all you need for your tank, often at a price far lower than, the LFS would have you believe.
you can of cause blindly buy the "aquarium" product. but could you stand being sent to bed by a black and white dog, controlled by a far off whistle?

as for people with RO units, not being shy with their money. i guess they can afford to be, as they are pi$$ing everybody else's water down the drain, for what is often no more than a perceived return. salt water, discus keepers and the like, excluded.

 

[windsor-aquatic]

Returning to the original question posed here. The only "safe" silicon to use, as has already been stated, is high modulus whis is identified on the tube as being suitable for aquarium use. Most low modulus brands have an anti-fungus additive which is not suitable for aquatic use. High modulus is generally defined as being water-proof under total submersion, as opposed to low modulus which is described as water-resistant, used, for example, to seal work-tops and the like. The difference in price, when compared to the outlay on an aquarium set-up, is minimal, and well worth the peace of mind its use will bring.

 

[raptorrex]

Returning to the original question posed here. The only "safe" silicon to use, as has already been stated, is high modulus whis is identified on the tube as being suitable for aquarium use. Most low modulus brands have an anti-fungus additive which is not suitable for aquatic use. High modulus is generally defined as being water-proof under total submersion, as opposed to low modulus which is described as water-resistant, used, for example, to seal work-tops and the like. The difference in price, when compared to the outlay on an aquarium set-up, is minimal, and well worth the peace of mind its use will bring.

i quite agree! however the stuff from these boat places is high modulus, all i have seen state it is aquarium safe. and cost a fraction of the price, an lfs would charge. £3.99 or so for a full sized tube.