Sodium Thiosulfate raise ph?

[guille2007]

Can sodium thiosulfate raise ph?, my ph has raised to 8.1 from 7.4 and I don't know why, it's bb tank sponge filter and power filter with foam and biological substrate hagen ceramic rings, nothing more.

[Graham]

As far as I know or have ever heard ST has no affect on pH. It's not unusual for pH to move around especially if there are plants, low CO2, low GH and KH...

[gg5190]

The chemical formula is Na2S203. Once this hits water the 2Na+ leaves because it is highly soluble. I don't think it would have an affect on pH cause its only an anion. It's possible that when it reduces Cl2 , it produces a basic solution. This is interesting, I want to see if i can find out more. I know for a fact that acids will readily attack the molecule breaking it down to sulfur compounds and water and that its only stable in neutral or basic conditions.

[pcsb23]

I believe sodium thiosulphate has a ph of 6.5.

[guille2007]

The chemical formula is Na2S203. Once this hits water the 2Na+ leaves because it is highly soluble. I don't think it would have an affect on pH cause its only an anion. It's possible that when it reduces Cl2 , it produces a basic solution. This is interesting, I want to see if i can find out more. I know for a fact that acids will readily attack the molecule breaking it down to sulfur compounds and water and that its only stable in neutral or basic conditions.

It did no happen me when I used aged water for WC ph kept constant at 7.4 I really had not tested ph for a long and now I notice this after using ST to remove chlorine.
I have heard that asian breeders use no ST but large stainless steel tanks and airation to age the water they use for WC

[guille2007]

The chemical formula is Na2S203. Once this hits water the 2Na+ leaves because it is highly soluble. I don't think it would have an affect on pH cause its only an anion. It's possible that when it reduces Cl2 , it produces a basic solution. This is interesting, I want to see if i can find out more. I know for a fact that acids will readily attack the molecule breaking it down to sulfur compounds and water and that its only stable in neutral or basic conditions.

Could a time limited zeolite filtration fix that?, I will test it

[gg5190]

i just found out that chemically most zeolite have a high affinity to calcium. That means they could have water softening properties! I really want to test this...

[guille2007]

I notice the ph raising after a large(65%) WC, in that case I had to use more ST than as normal of 20% WC I do daily, two questions here:

1-the sodium salt in water cause by ST action could move up the ph?

2- Could zeolite filtration remove those sodium salts it?, it's currently in testing by me

[Graham]

The sodium isn't set free all on it's own and you wouldn't want to remove it from the water to start with. The fish use it as they do chloride.

Na2S2O3 + CI2 + H2O (to) Na2S04 + S + 2HCI

[Polar_Bear]

What you need to do is test your tap water, most likely your carbonate hardness has risen taking your pH up with it.

[guille2007]

My tap water ph is 7.4 , anyway I will test kh to see

[guille2007]

Here are my parameters:

Tank gh 160 kh 110 ph 8.1

Main tap water gh 200 kh 130 ph 7.4, ph raised to 8.4 after aeration for 5 hours

kh is very high, what way to fix or lower that other solution than RO unit?, zeolite filtration seems to do something but not sure yet

[gg5190]

Save the time, money and go with RO/DI. Its one of the best things you can do. And there not that expensive! But they are up there.

[guille2007]

i just found out that chemically most zeolite have a high affinity to calcium. That means they could have water softening properties! I really want to test this...

Zeolite seems to do it its work after 3 days added to filtering, GH from 11.5 to 10, KH from 7.5 to 5.

Will test it again after a week

[Graham]

Just remember that KH is a constantly dropping number. Every biological process in the tank works at dropping KH.

Calcium and bicarbonates,,,as in GH and KH are intertwined so don't rely on zeolites to overall affect these levels

[Rod]

It did no happen me when I used aged water for WC ph kept constant at 7.4 I really had not tested ph for a long and now I notice this after using ST to remove chlorine.
I have heard that asian breeders use no ST but large stainless steel tanks and airation to age the water they use for WC

Most of the farms i visited in asia use activated carbon and then store the water in huge fibreglass rainwater tanks under aeration. Most of them use ST before a water change.....just to make sure!!! At least that is what they told me, one even showed me his bag of st, saying to me on the quiet that it is his secret ingredient. :D

Personally i have not used st for many years, activated carbon and aeration is all that is nessasary with my tapwater.

Rod:)

[guille2007]

Most of the farms i visited in asia use activated carbon and then store the water in huge fibreglass rainwater tanks under aeration. Most of them use ST before a water change.....just to make sure!!! At least that is what they told me, one even showed me his bag of st, saying to me on the quiet that it is his secret ingredient. :D

Personally i have not used st for many years, activated carbon and aeration is all that is nessasary with my tapwater.

Rod:)

After reading all what experimented ppl have told and showed here I would have to accept that the ph increasing was not caused by ST but really I had not any ph problems while I was using just aged water , I switched to ST after increasing the daily WC from 10% to 40% so I didn't have enough aged water to use

[guille2007]

Just remember that KH is a constantly dropping number. Every biological process in the tank works at dropping KH.

Calcium and bicarbonates,,,as in GH and KH are intertwined so don't rely on zeolites to overall affect these levels

What are zeolites?

These are naturally occurring types of minerals, although because of their usefulness as molecular sieves they can now be artificially produced. In their natural form they are aluminosilicates, which are normal silicate minerals containing aluminium. The structure is such that these minerals can loosely bind positive charged ions, usually sodium.

They act as ion-exchangers and 'swap' their sodium ions, for other positively charged ions, for example calcium or ammonium. So they are often used for water softening to remove hardness-forming calcium ions. Fish keepers can make use of this unusual characteristic and employ them to remove ammonia (or more strictly ammonium - NH4+) from the water.

It was taken from here:

http://www.fishdoc.co.uk/water/zeolite.htm