Sandstone..good or bad?

[AnnAlfie]

There is a lot of mixed results online as to the use of sandstone in fish tanks. Personally, I have a piece of sandstone however my tank was cycled 6 months in advance of adding fish. The sandstone was given to me from a builder. I washed the stone and poured boiling water over it to kill any nasty beasties that might have been lurking then soaked it for almost 2 weeks. I then added the stone to the tank. I did regular tests on the water over the course of 6 months. The stone had no effect on the water at all and after 6 months of cycling and testing it still had no effect.
Sandstone can contain a lot of metals etc...so would not be advisable but if you're willing to do 6 months of testing to deem it safe then you maybe alright with it
Please note that this thread is purely my own experience and opinions. If any persons use sandstone in their tanks, they do so at their own risk.
I'm not a professional so it's always best to research or ask professional advice if you are unsure.

 

[eaglesaquarium]

Members are reminded to act in a respectful manner at all times to other members. As the old saying goes, 'if you have nothing nice to say to someone, then don't say anything at all.'

 

[eaglesaquarium]

Let's keep the discussion to the topic at hand... sandstone.

 

[AnnAlfie]

Let's keep the discussion to the topic at hand... sandstone.

Indeed Thank you

 

[StevenF]

Sandstone is mainly sand cemented together with minerals. What this minerals are make a big difference on how fast the rock will effect your water parameters. some minerals just don't dissolve easily or only dissolve under very specific conditions. Calcium carbonate for example only dissolves in low PH conditions and near PH of 7 only about 0.013grams per liter will dissolve.. If PH is 7 or higher it won't dissolve in fresh water. If might be very hard or impossible to see the small changes that occur as the carbonate dissolves. It will dissolve but it will tank many years to the rock to turn to sand.

However if the mineral is Calcium sulfate (gypsum) it will dissolve at a faster rate. Up to 2grams per liter of water during water change. At this rate the rock will eventually turn to a pile of sand in about a year or so in a large tank. You would also see a noticeable change in GH during that dime.

Note on many sites it is recommended to apply vinagar to the rock to test them. If the water fizzes the recommendation is not to use it since it will effect ph. However in my above examples sandstone with calcium carbonate will fizz. However sandstone with gypsum will not fizz when exposed to vinagar. So in these cases the vinagar test you tell you its ok add the gypsum sandstone and not to use the calcium carbonate sandstone. However the rock most likely to affect your waters GH is the gypsum sandstone.

The best way to test a rock is to put it in a large bucket of water and to carefully monitor GH and KH.

However all that said the minerals cementing the sand together is typically not made from one miner. Typically many different minerals are mixed together. If the sandstone has mercury or copper it could be very dangerous to your fish. Especially if the minerals dissolve rapidly. So overall you should be cautious with sandstone. There is no easy way to know if it is dangerous or not.

 

[AnnAlfie]

Sandstone is mainly sand cemented together with minerals. What this minerals are make a big difference on how fast the rock will effect your water parameters. some minerals just don't dissolve easily or only dissolve under very specific conditions. Calcium carbonate for example only dissolves in low PH conditions and near PH of 7 only about 0.013grams per liter will dissolve.. If PH is 7 or higher it won't dissolve in fresh water. If might be very hard or impossible to see the small changes that occur as the carbonate dissolves. It will dissolve but it will tank many years to the rock to turn to sand.

However if the mineral is Calcium sulfate (gypsum) it will dissolve at a faster rate. Up to 2grams per liter of water during water change. At this rate the rock will eventually turn to a pile of sand in about a year or so in a large tank. You would also see a noticeable change in GH during that dime.

Note on many sites it is recommended to apply vinagar to the rock to test them. If the water fizzes the recommendation is not to use it since it will effect ph. However in my above examples sandstone with calcium carbonate will fizz. However sandstone with gypsum will not fizz when exposed to vinagar. So in these cases the vinagar test you tell you its ok add the gypsum sandstone and not to use the calcium carbonate sandstone. However the rock most likely to affect your waters GH is the gypsum sandstone.

The best way to test a rock is to put it in a large bucket of water and to carefully monitor GH and KH.

However all that said the minerals cementing the sand together is typically not made from one miner. Typically many different minerals are mixed together. If the sandstone has mercury or copper it could be very dangerous to your fish. Especially if the minerals dissolve rapidly. So overall you should be cautious with sandstone. There is no easy way to know if it is dangerous or not.

Wow. You know your stuff. Very informative. Thanks.