Non Silicate Sand

[afriend]

I'm considering adding a thin layer of non silicate sand to my aquarium containing adult discus. My understanding is that silicate sand can lead to diatom problems, so I thought it would be best not to use it. One type of non silicate sand is crushed marble which is calcium carbonate. The type I am considering is sold under the trade name "PlayBox" sand and is stated as 99.9% silicate free.

Anyone have experience with this product OR have knowledge of how calcium carbonate can affect the water chemistry in my aquarium? I'm a novice in this area, so any and all responses would be greatly appreciated.

Paul

[dirtyplants]

a chemical compound with the formula CaCO3. It is a common substance found in rocks in all parts of the world, and is the main component of shells of marine organisms, snails, coal balls, pearls, and eggshells. Calcium carbonate is the active ingredient in agricultural lime, and is created when Ca ions in hard water react with carbonate ions creating limescale. It is commonly used medicinally as a calcium supplement or as an antacid, but excessive consumption can be hazardous. This also reacts with CO2, I beleive calcium bicarbonate, reacts with acid releasing carbon dioxide.
I would not use it unless my water were very acidic or soft.

[afriend]

a chemical compound with the formula CaCO3. It is a common substance found in rocks in all parts of the world, and is the main component of shells of marine organisms, snails, coal balls, pearls, and eggshells. Calcium carbonate is the active ingredient in agricultural lime, and is created when Ca ions in hard water react with carbonate ions creating limescale. It is commonly used medicinally as a calcium supplement or as an antacid, but excessive consumption can be hazardous. This also reacts with CO2, I beleive calcium bicarbonate, reacts with acid releasing carbon dioxide.
I would not use it unless my water were very acidic or soft.

dirtyplants,

My understanding is that calcium carbonate is commonly found in drinking water. Is this right? Can you please explain why one should not use it unless the water is very acidic? What would happen to the water if it were alkaline? Will the addition of calcium carbonate in the form of sand change the PH? If so, how? My water has a TDS of 83ppm. Is this soft enough?

Thank You for your reply.

Paul

[dirtyplants]

it reacts with strong acids, releasing carbon dioxide:
CaCO3(s) + 2 HCl(aq) → CaCl2(aq) + CO2(g) + H2O(l)
it releases carbon dioxide on heating, called a thermal decomposition reaction, or calcination, (to above 840 °C in the case of CaCO3), to form calcium oxide, commonly called quicklime, with reaction enthalpy 178 kJ / mole:
CaCO3(s) → CaO(s) + CO2(g)
Calcium carbonate will react with water that is saturated with carbon dioxide to form the soluble calcium bicarbonate.

CaCO3 + CO2 + H2O → Ca(HCO3)2
This reaction is important in the erosion of carbonate rocks, forming caverns, and leads to hard water in many regions.

An unusual form of calcium carbonate is ikaite with crystal water, CaCO3·6H2O. Ikaite is stable only below 6 °C.

Preparation[edit]


I beleive this for play sand is just fine, for discus I beleive it will alkalize the water. If you have very soft water, or acid based water this sand would be good depending on the acid base and how hard you want the water to become. Many use Indian Almond Leaves to do the reverse, acidify water or remove minerals by RO. If you are in need of (harder)/mineralized water then maybe this would be a good product. For me it would drive my alkalinity way up. You could test it, GH,KH, pH throw it in water let it set for a period and test your parameters. Maybe it would not break down quickly, for me just makes the waters parameters more complicated.


Calcium carbonate is added to swimming pools, as a pH corrector for maintaining alkalinity and offsetting the acidic properties of the disinfectant agent.

[OC Discus]

Coree,

Paul and I are looking into non silica sand to avoid feeding diatoms in the tank. What will crushed coral, aragonite, and other types of sand found in fish stores do to the chemistry of the aquarium?

I remember someone in SD advising me against silica sand a few months ago because of the silicates that feed diatom. Another member said the glass itself is silica, and diatom forms on bare bottom tanks.

I'm sure large daily water changes is the preferred way to remove all undesireable elements from the water. But what is your opinion of the build up of silicate and phosphate as a result of sand, and what type is the best option.

Thanks.

[afriend]

You could test it, GH,KH, pH throw it in water let it set for a period and test your parameters. Maybe it would not break down quickly, for me just makes the waters parameters more complicated.

Coree,

Thanks for the input and the chemistry lesson. I know just about enough about chemistry to decipher the equations.

Have decided to follow your advice and test the water parameters with the non-silica sand in a separate aquarium. Ordered the sand this afternoon. Will post back in a couple of weeks when I have the results. I like tests like this.

Paul

[Fundulopanchax]

Carbonate in soft water that is not already alkaline will rapidly increase pH and hardness (where rapid is a few days). If you change a large quantity of water with your soft water, your chemistry will dramatically change and then get rebuffered by the carbonate. This is not good for the fishes. Certainly do not use aragonite and similar. All of these are excellent for Rift Lake cichlids that require hard alkaline water and marine aquaria but not for South American fishes.

While silica sand before it is washed may release small quantities of silicates (not particularly soluble though, just very small particles; the sand itself does not release silicates - it is essentially the same material as your aquarium glass. Silica sand does not lead to diatom outbreaks.

Ron

[discuspaul]

Agree with Ron above. To my knowledge, most commercially marketed silica sands, pool filter sand in particular, are inert and release no silicates into the water.

[DiscusLoverJeff]

Agree with Ron above. To my knowledge, most commercially marketed silica sands, pool filter sand in particular, are inert and release no silicates into the water.

I have not had any trouble with Pool Filter Sand going on 3 years now.

[afriend]

I have not had any trouble with Pool Filter Sand going on 3 years now.

Jeff,

So you have used silica sand for going on three years without any problems with diatoms?

Can you tell me where you obtained it from and what kind it is?

Thanks for your help.

Paul

[afriend]

Carbonate in soft water that is not already alkaline will rapidly increase pH and hardness (where rapid is a few days). If you change a large quantity of water with your soft water, your chemistry will dramatically change and then get rebuffered by the carbonate.

Of course. (Dumb me for not thinking) This is the basis for carbonate hardness.

Thanks for your help.

Paul

[dirtyplants]

Carbonate in soft water that is not already alkaline will rapidly increase pH and hardness (where rapid is a few days). If you change a large quantity of water with your soft water, your chemistry will dramatically change and then get rebuffered by the carbonate. This is not good for the fishes. Certainly do not use aragonite and similar. All of these are excellent for Rift Lake cichlids that require hard alkaline water and marine aquaria but not for South American fishes.

While silica sand before it is washed may release small quantities of silicates (not particularly soluble though, just very small particles; the sand itself does not release silicates - it is essentially the same material as your aquarium glass. Silica sand does not lead to diatom outbreaks.

Ron has got it right. The very best sand is volcanic sand from what I understand, you can order it on the net but shipping for large quantities can be expensive, a good quality pool sand, should be fine. Many people on the forum use it and so do I.

[Tazalanche]

Blaming sand for diatoms is inaccurate. There is more silica in the glass than in the amount of sand we use as substrate.

[afriend]

Blaming sand for diatoms is inaccurate. There is more silica in the glass than in the amount of sand we use as substrate.

Thanks, I'm beginning to get the picture here.

Paul

[Argentum]

Silica is the main component of glass and is a very inert material, meaning it will not react with your water. CaCO3 "Calcium Carbonate" will increase your hardness and will react (dissolve) with your water at low pH raising your Hardness and pH.

Silica sand will be the better option like PFS, and this is what is used to manufacture glass in the first place. and is composed mainly of Silicon Oxide.

Source: I am a Chemist :)

[afriend]

Silica is the main component of glass and is a very inert material, meaning it will not react with your water. CaCO3 "Calcium Carbonate" will increase your hardness and will react (dissolve) with your water at low pH raising your Hardness and pH.

Argentum,

This is a very direct and precise answer, and exactly what I was looking for. Interesting enough, I knew about carbonate hardness and pH, but for some reason (old age perhaps) did not think of it. Glad to know that you're a chemist, maybe I can rely on you next time I need some advice.


Silica sand will be the better option like PFS, and this is what is used to manufacture glass in the first place. and is composed mainly of Silicon Oxide.

Can you please explain what PFS means?

Thanks,

Paul

[Tazalanche]

Can you please explain what PFS means?

Thanks,

PaulPool
Filter
Sand

Here's my low cost recommendation: Ace Hardware Aqua Quartz® 50lbs Pool Filter Sand (http://www.acehardware.com/product/index.jsp?productId=11683357&cp=2568443.2568445.2598564.2598616.3719925.1260313 )

It is about $13 online, but regularly goes on sale in store for either $9 or $10. One bag is about right for a 55 gallon tank, with a little extra to spare if you don't want it at least 1" deep. Compared to others we tried, there is minimal rinsing involved.

We have had it in a 20L, 54 corner, two 55s & a 135 for about a year with no issues. Many others here use it with no issues too.

[afriend]

Pool
Filter
Sand

Here's my low cost recommendation: Ace Hardware Aqua Quartz® 50lbs Pool Filter Sand (http://www.acehardware.com/product/index.jsp?productId=11683357&cp=2568443.2568445.2598564.2598616.3719925.1260313 )

It is about $13 online, but regularly goes on sale in store for either $9 or $10. One bag is about right for a 55 gallon tank, with a little extra to spare if you don't want it at least 1" deep.

We have had it in a 20L, 54 corner, two 55s & a 135 for about a year with no issues. Many others here use it with no issues too.

Tazalanche,

Another direct precise answer. SD is a really great forum.

Thank you very much.

Paul

[nvladik]

I highly recommend Mystic White PFS, if you can get your hands on some. Nice white color, quality is best of what i've seen. Same price, about $12 for 50lb, just have to find it.

[afriend]

I highly recommend Mystic White PFS, if you can get your hands on some. Nice white color, quality is best of what i've seen. Same price, about $12 for 50lb, just have to find it.

I'll check it out.

Thanks,

Paul

[nvladik]

I'll check it out.

Thanks,

Paul

Paul if you are in NY/NJ area, I have a place to get it from.

[OC Discus]

I highly recommend Mystic White PFS, if you can get your hands on some. Nice white color, quality is best of what i've seen. Same price, about $12 for 50lb, just have to find it.

Who is a retailer of mystic white?

[Argentum]

Argentum,

Glad to know that you're a chemist, maybe I can rely on you next time I need some advice.


You are welcome, anytime when it comes to chemistry.

Regarding Discus I am just a beginner

[nvladik]

Who is a retailer of mystic white?

Random retailers carry it, I use Naso Pools here locally.