# Saf-T-Sorb



## aquabillpers (Apr 13, 2006)

I recently decide to try Saf-T-Sorb in place of the soil substrate in an NPT. From what I'd read it offers a number of advantages, so I bought a lifetime supply for $7.

I rinsed it several times over a week. I remember thinking that it was very "dirty". The rinse water never really got clear but I added about an inch of the STS to a 10 gallon tank anyway and filled the tank with well water.

The water in the tank immediately became solid brown in color. In 10 hours the color lightened but it still was opaque. Filtering made it worse, and the filter picked up very little material.

Today. after a week, I can just make out the back of the tank, but obviously this tank isn't going to work. Michael uses it as a soil cap with success so it must be something I did. Any ideas?

BTW, I have some topsoil that's been soaking for 6 months, for just such an emergency. <g>

Bill


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## mistergreen (Mar 3, 2007)

You might want to cap it and do a water change. 
Also, you'll need to add nutrients in the substrate. The baked clay doesn't have any but has high CEC.


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## Michael (Jul 20, 2010)

Weird! I use it as a cap all the time, and Seattle Aquarist uses it as a stand-alone substrate with fertilization. It never washes completely clean, and the tank is usually a little cloudy for a day or two. But I've never had the problems you describe.

It is possible that the manufacturer changed the process or ingredients in the batch you got. After all, they don't make this stuff for aquaria, and don't care if it makes our water cloudy. It has been a long time since I bought any new STS.


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## dwalstad (Apr 14, 2006)

I put a thin layer in all my guppy tanks about 6 months ago. It started breaking down and continues to break down, making the water a little cloudy. I wish I had used plain gravel or some other medium that doesn't break down. Turface? I bought my STS last summer.

I would not use STS in place of soil. Doesn't have any nutrients and such a large volume of STS would probably change the water chemistry dramatically.


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## Seattle_Aquarist (Mar 7, 2008)

Hi @aquabillpershttps://www.aquaticplantcentral.com/forumapc/members/aquabillpers.html,

I've used Safe-t-sorb for several years now. When starting a new tank I never wash or even rinse it. I used to try to rinse it but as noted it 'never rinses clean' ...... that is because it is clay. I now just put it into the tank the dry, cover it with wax paper and an plate so it isn't disturbed by filling, and start up my filter. *Here is the 45 gallon I did shortly before the 1st of the year.* I probably would have used about 1/2 the number of DIY Osmocote Root Tabs (purchased on Ebay) in future set-ups. Hope this helps! -Roy

This is what the tank looked like after about 24 hours. I was running a canister and an HOB filter on the tank.


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## hoppycalif (Apr 7, 2005)

I bought a bag of STS about a year ago, and used it as the gravel for two tanks, which ran for about 10 months. About 2 weeks ago, now that I am in a different apartment, I set up one of the tanks, and again used it as the gravel, this time over mineralized topsoil from my tiny back yard. So far no problems of any kind with it. The water took about 3 days to clear up well when I first flooded the tank, but it hasn't been cloudy since then. I suspect the particles will gradually change to just fine clay over several years, but no sign of that yet.


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## aquabillpers (Apr 13, 2006)

Thanks so much to all of you for your help!

Maybe I was overly zealous in washing the STS, like a raccoon washing his sugar cube treat. Next time, I'll follow Seattle's example.

If it doesn't work this time, I'ii buy another batch.

Michael, how deep do you make your STS cap? Thanks.

Mistergreen, I had planed to overfertilize the tank with Flourish, let it sit for a few days, then replace the water with fresh well water. Then, plant a few easy growing plants and add 10 - 15 male Endler's.

Thanks again for your help!

Bill


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## GadgetGirl (Sep 25, 2013)

I've never used the STS brand but have used Oil-Dri (same product) many times, as recent as a month ago with a new bag. No problems at all and I've rinsed the hell out of it! I have no explanationion for what happened with yours. 

But....I'm always really careful about not disturbing my substrate layers when filling the tank. I put a plate on top and pour water on top of that. 

Sent from my Pixel 4 XL using Tapatalk


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## Michael (Jul 20, 2010)

aquabillpers, the STS cap in my tanks is never more than an inch deep. Unless I make a mistake of course.


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## aquabillpers (Apr 13, 2006)

Here's an update.

After 3 days the water cleared a lot, but it was still too cloudy for use in an aquarium, so I broke the tank down and tried again.

I hypothesized that my vigorous cleaning of the STS might have damaged the particles, so I decided this time to use the STS "as is", as Seattle does. But as I poured it into a transfer pail, it gave off a lot of dust, enough to make me cough. I didn't want that in the aquarium so I decided to modify the "as if" procedure and gently rinse the STS.

I filled a 5 gallon pail with well water and gently poured the STS into it. Almost immediately the water became opaque! I debated repeating the rinse and decided against it. 

I poured the rinsed STS into a 10 gallon tank to a depth 1 inch, and added 5 inches of water. After 12 hours the water was cloudy but not bad as in the first test. After 3 days the water was clear enough for aquarium use. But gently stirring the STSit with a finger caused clouds of particles to rise
and remain suspended.

I decided that STS would be a pain to work with as the main substrate. I am going to continue rinsing what I have until the water gets clear and then us it as a cap over the cheap topsoil that is now soaking.

Observation: Michael commented that STS is not manufactured for aquarium use. Thus, there could be variations in different batches that reduce its utility as an aquarium substrate, that doesn't affect its use as an absorbent. Given the both positive and negative experiences that have been reported, that sounds like a pretty good explanation. 

Thanks again to everybody!

Bill


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## GadgetGirl (Sep 25, 2013)

Something is just not right with that bag! I have never had this happen and I rinse the crap out of it. Usually it settles very quickly.

Sent from my moto g power using Tapatalk


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## ChuckM (Mar 19, 2020)

GadgetGirl said:


> I've never used the STS brand but have used Oil-Dri (same product) many times, as recent as a month ago with a new bag. No problems at all and I've rinsed the hell out of it! I have no explanationion for what happened with yours.
> 
> But....I'm always really careful about not disturbing my substrate layers when filling the tank. I put a plate on top and pour water on top of that.
> 
> Sent from my Pixel 4 XL using Tapatalk


Another Oil Dri fan here (US$7.99/40lbs, and I'm interested). I chose it primarily based on the anoxic denitrification ideas of Jay's Aquarium, Dr. Novak and Jean Jaubert (and before I came across Ms. Walstad's work). It's been in place in a 65 gallon and a 6 gallon planted community tanks for just over two years and I'm quite satisfied with it.

When I first built these tanks I did lots of rinsing of it in a wheelbarrow and saw that there was no way to get the water to run clear, so after 20 minutes or so of flushing and gentle agitation I went ahead with it and after 24 hours or so with HOBs running the tank cleared.

It does take some care with gravel vacuuming, but I don't have to do much because the mulm on the bottom tends to get absorbed into the substrate. Planting and transplanting etc. though can cause cloudiness but that dissipates within 15-30 minutes.


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## aquabillpers (Apr 13, 2006)

I ran a HOB filter for 24 hours. The floss was only slightly colored and the tank was still murky. Very fibe particles!

BTW, in more than 15 years of keeping soil-based tanks with gravel caps, I have never had a problem with cloudy water. Any cloudiness disappears in an hour or 2 without filtering.

Bill


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## dwalstad (Apr 14, 2006)

STS has a very high cation exchange capacity and can change the water chemistry. In my pilot experiments, it lowered pH and KH but raised the GH. If you use STS, I would check these parameters and be prepared to go through an adjustment phase. Eventually, it will--like soil--stabilize. 

When I added some sodium bicarbonate (baking soda) to bring KH and pH up, it helped clear the water.


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## GadgetGirl (Sep 25, 2013)

dwalstad said:


> STS has a very high cation exchange capacity and can change the water chemistry. In my pilot experiments, it lowered pH and KH but raised the GH. If you use STS, I would check these parameters and be prepared to go through an adjustment phase. Eventually, it will--like soil--stabilize.
> 
> When I added some sodium bicarbonate (baking soda) to bring KH and pH up, it helped clear the water.


Isn't that the truth! My ph dropped from 7.0 to probably less that 6 and my already low kh of 3 dropped to 0. 
When I added a bit of baking soda to raise the parameters, it only held for about 24 hrs, then dropped again. Should I keep adding? Or is this fruitless until things equilibrate?


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## Michael (Jul 20, 2010)

Substrate choice should be made with your water source chemistry in mind. My tap water is moderately hard and strongly buffered to pH 7.8. Safe-T-Sorb has almost no effect on MY water chemistry. Results would be very different if I had soft, weakly buffered water.


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## dwalstad (Apr 14, 2006)

GadgetGirl said:


> Isn't that the truth! My ph dropped from 7.0 to probably less that 6 and my already low kh of 3 dropped to 0.
> When I added a bit of baking soda to raise the parameters, it only held for about 24 hrs, then dropped again. Should I keep adding? Or is this fruitless until things equilibrate?


Good you checked. Since you have softwater, your situation is different than Michael's. I would add more baking soda. The STS is going to take up all the ions/salts out of the water until the binding sites on the clay particles are filled. (My book, page 126) Right now those binding sites are not filled. Only then will the STS stop lowering KH and pH.

STS will take up plant nutrients like Ca, Mg, K so make sure that you are adding these are other ions/salts as well as the baking soda.


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## mistergreen (Mar 3, 2007)

Interesting. Maybe before putting it in my tank, I’d let it soak in Ca, Mg, K for a few days.


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## GadgetGirl (Sep 25, 2013)

dwalstad said:


> The STS is going to take up all the ions/salts out of the water until the binding sites on the clay particles are filled. (My book, page 126) Right now those binding sites are not filled. Only then will the STS stop lowering KH and pH.
> 
> STS will take up plant nutrients like Ca, Mg, K so make sure that you are adding these are other ions/salts as well as the baking soda.


Thank you for the advice, Diana. I'm reviewing the section on Nutrient Binding.


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## GadgetGirl (Sep 25, 2013)

mistergreen said:


> Interesting. Maybe before putting it in my tank, I'd let it soak in Ca, Mg, K for a few days.


That's a very interesting idea!


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## ChuckM (Mar 19, 2020)

dwalstad said:


> Good you checked. Since you have softwater, your situation is different than Michael's. I would add more baking soda. The STS is going to take up all the ions/salts out of the water until the binding sites on the clay particles are filled. (My book, page 126) Right now those binding sites are not filled. Only then will the STS stop lowering KH and pH.
> 
> STS will take up plant nutrients like Ca, Mg, K so make sure that you are adding these are other ions/salts as well as the baking soda.


Can I presume this applies to any baked clay product?


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## dwalstad (Apr 14, 2006)

I would not assume anything. 

In thinking about why STS is so "ion hungry," let me offer a theory. If STS is mined as big rocks and then crushed to make smaller particle sizes, the raw clay sheets of silica are suddenly opened up to expose their _unfilled_ binding sites.

In contrast, natural clay particles have been exposed to ions from water for maybe years or centuries. Their binding sites have already filled up with all the Ca, Mg, Na, K that naturally occurs in surface water and groundwater. So a clay dug up out of the earth would seem to me to already have its binding site filled up.

I'm not sure that the baking process would remove bound ions. And there's different levels of "baking." I recommend doing a bottle test and measuring the KH, GH and pH.


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## mistergreen (Mar 3, 2007)

Also, different clays have different levels of CEC. STS is made of Montmorillonite Clay which has the highest. Their structure expand when hydrate for more surface area.


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## GadgetGirl (Sep 25, 2013)

mistergreen said:


> Interesting. Maybe before putting it in my tank, I'd let it soak in Ca, Mg, K for a few days.


I just happened to run across this today: http://www.theplantedtank.co.uk/akadama.htm

Read the section called "Planning"


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## mistergreen (Mar 3, 2007)

Coconut coir is used for chemical mop up too. Its CEC is very high. It'll drop your water params too.


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## hoppycalif (Apr 7, 2005)

I'm about ready to jump off the bandwagon for Safe-T-Sorb! I now have my 30 gallon tank set up with mineralized topsoil capped with Safe-T-Sorb. My plants are growing, but they are all generally referred to as weeds, and they are not growing nearly as fast as I remember from the days when I was using pool filter sand as a cap. That caused me to think back to all of my tries with Safe-T-Sorb as a cap, and I think in every case the plant growth was slow. (If you wonder why I kept using it, just remember how big a bag of it you get for such a small cost. The bag is now empty!)

Diana has mentioned the effect Safe-T-Sorb can have on the water, by adsorbing so much of the cations, even lowering the pH. My tank isn't an El Natural tank now - I'm fertilizing with NPK and traces, so I know I'm mixing up different types of tanks. I am wondering if I would have much better results going back to my pool filter sand. In fact I suspect my next set-up will be just pool filter sand with no soil, and maybe just guppies in it! In other words, my age 16 aquarium.


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## mistergreen (Mar 3, 2007)

hoppycalif said:


> I'm about ready to jump off the bandwagon for Safe-T-Sorb! I now have my 30 gallon tank set up with mineralized topsoil capped with Safe-T-Sorb. My plants are growing, but they are all generally referred to as weeds, and they are not growing nearly as fast as I remember from the days when I was using pool filter sand as a cap. That caused me to think back to all of my tries with Safe-T-Sorb as a cap, and I think in every case the plant growth was slow. (If you wonder why I kept using it, just remember how big a bag of it you get for such a small cost. The bag is now empty!)
> 
> Diana has mentioned the effect Safe-T-Sorb can have on the water, by adsorbing so much of the cations, even lowering the pH. My tank isn't an El Natural tank now - I'm fertilizing with NPK and traces, so I know I'm mixing up different types of tanks. I am wondering if I would have much better results going back to my pool filter sand. In fact I suspect my next set-up will be just pool filter sand with no soil, and maybe just guppies in it! In other words, my age 16 aquarium.


Sounds like a side by side experiment waiting to happen. I've heard the same problem with people using too much coco coir in their soil when growing terrestrials. The coir would soak up the nutrients that would otherwise go to the plants.


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## GadgetGirl (Sep 25, 2013)

I wonder if some trace elements would help during the transition period until the STS equilibrates? (I already use K as per Diana's water hardness recipe)


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## hoppycalif (Apr 7, 2005)

mistergreen said:


> Sounds like a side by side experiment waiting to happen. I've heard the same problem with people using too much coco coir in their soil when growing terrestrials. The coir would soak up the nutrients that would otherwise go to the plants.


It would be a very good experiment, but now I have no STS, so I would find myself with another huge bag of it and would just have to use it up. But, I may decide to do it anyway!


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## hoppycalif (Apr 7, 2005)

GadgetGirl said:


> I wonder if some trace elements would help during the transition period until the STS equilibrates? (I already use K as per Diana's water hardness recipe)


Ammonium is a cation, so if the ammonia in the dirt is ammonium that would possibly slow down the plant growth. Traces wouldn't help that. Also, I have no feel at all about how much cations of iron, etc. can be adsorbed by the STS before it is saturated. I've been dosing trace elements with little effect that I can see, but if it is all quickly adsorbed by the STS I could understand that. If the plants finally decide to grow normally that would be suggestive about how the STS is working. The plants are almost all stem plants, so they get most of their nutrients from the water, not the substrate.


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## mistergreen (Mar 3, 2007)

Some stems do take nutrients through the roots. Sounds like most plant take in nutrients though roots and leaves. Only ones for sure only through their leaves are epiphytes, ferns, anubias, etc...


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## hoppycalif (Apr 7, 2005)

mistergreen said:


> Some stems do take nutrients through the roots. Sounds like most plant take in nutrients though roots and leaves. Only ones for sure only through their leaves are epiphytes, ferns, anubias, etc...


When you first plant a new tank the stem plants don't have roots, and some never do grow substantial roots. What I am seeing is very slow growth of normally rapid growing stem plants. Eventually the stem plants start growing at a normal pace. I think this has been true for every tank I used STS for a cap layer in. I wasn't expecting this and didn't keep a log or anything, but it seems like this is typical for my STS capped set-ups. Since my memory may be flawed I would want to experiment to try to see if it is real or just my imagination.


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## mistergreen (Mar 3, 2007)

The only stems I think don't grow roots are anarchis & hornwort. I think they prefer to float.
Yeah, other stems don't grow extensive roots like rosettes but they are roots, I think mainly, they don't propagate through runners like rosettes. They even grow roots on the side of the stems like my Rotala.


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## aquabillpers (Apr 13, 2006)

When I started this thread I wanted to find out if STS - appropriately enriched - could replace soil as a substrate. I have found out so much morel

Some people have success using it as a substrate or a cap. Others have had problems. Diane reported that STS can cause significant changes in water chemistry in some kinds of water. If nothing else, it seems that using STS adds another variable to be considered should problems develop in a tank.

My own experiment ended when I tried to get my sample sufficiently clean that it would not make an aquarium cloudy when it was disturbed. I rinsed it under running water until it was clear, then stirred it vigorously. After stirring the water became opaque and brownish-black in color. I emptied the dirty water and repeated the process about seven times, with the same result.

I then noticed that there was only about half of the STS left. Apparently it is relatively fragile and doesn't take well to rough treatment. I wonder if it slowly dissolves?

I'm going to give my remaing STS to my mechanic.

Bill


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## ChuckM (Mar 19, 2020)

aquabillpers said:


> When I started this thread I wanted to find out if STS - appropriately enriched - could replace soil as a substrate. I have found out so much morel
> 
> Some people have success using it as a substrate or a cap. Others have had problems. Diane reported that STS can cause significant changes in water chemistry in some kinds of water. If nothing else, it seems that using STS adds another variable to be considered should problems develop in a tank.
> 
> ...


I think you came to the wrong conclusion with STS. Because this forum is more about Ms. Walstad's planted tank protocols (which is why I'm here too) I won't go into why I like it, I did already in a previous post.
Remember it's basically baked, or fired, clay. I think it's probably a lower temperature fire than ceramic ware, and certainly below porcelain. More like a "bisque" firing. So it's somewhat fragile and agitation easily causes crumbling which is what you're seeing in the rinse water. As it happens, I have a background in ceramics and am familiar with what happens if you rub two pieces of fired (but not glazed) clay and they crumble and flake very easily.
As I said earlier, don't sweat it if the water doesn't run clear. It probably won't till all the product is gone! In my case I needed about 60 lbs and used a wheelbarrow and garden hose to flush it 3-4 times with very gentle agitation by hand. When first loaded in the tank (65 gallon) the water was truly dense brown, but after 24 hours it was nearly clear.
I try not to disturb it too much, I don't tend to rescape very often. If I do there is some stirring up and cloudiness for a half hour or so but it settles out. As far as a threat to the live stock, remember where they evolved; in muddy dirty water probably nowhere near as clean and clear as our aquariums. My fish, snails and shrimp seem to be content with it.


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## dwalstad (Apr 14, 2006)

ChuckM said:


> As far as a threat to the live stock, remember where they evolved; in muddy dirty water probably nowhere near as clean and clear as our aquariums. My fish, snails and shrimp seem to be content with it.


Good input. Last year, I put STS in all my 8 guppy tanks just to cover the glass bottom with about 1/4 inch. It's so inexpensive! It slowly crumbles into fine particles, so I have about 5-10% mud along with the original STS gravel. It doesn't cloud the water that much. (Remember that gummy bacterial biofilms help hold clay particles together.)

STS experts have also noticed the slow disintegration of STS gravel into fine, clay like particles. Washing the gravel more than once doesn't help.

Fish, shrimp, and plants do well with it. I think it is a viable option for those that don't care if the water is less than crystal clear.


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## mistergreen (Mar 3, 2007)

Interesting. I saw a video of the processing for Oil-dri which I guess is the same stuff. They only dry the clay, not kiln bake to make it water proof. Sounds like it would make a good soil amendment.


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## GadgetGirl (Sep 25, 2013)

I have used Oil-Dri for years with no problems other than the buffering issue. It never clouds the water. Even if it gets a bit disturbed, it quickly settles down. I've never seen any deterioration. I used Walmarts Special Kitty once in a small tank and didn't like it as it seemed to be be "muddier" like it was deteriorating. Maybe the STS is more like kitty litter?
I like the Oil-Dri better than sand because of the natural look. Sand seems to get so nasty looking after awhile. I know that's natural too but I just don't like the way it looks!


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## dwalstad (Apr 14, 2006)

How fast these grease soakers crumbles depends on the baking temperature. The higher the temperature, the more it solidifies. I would expect considerable variation between brands, purchase times, etc. Oil and grease clean-up is not yet standardized.


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## GadgetGirl (Sep 25, 2013)

You mean mechanics aren't taking careful measurements as to how much grease is being absorbed!? ml grease per g Oil-Dri?
But seriously, I don't think it's a very standardized industry either! Never tried STS as it's not readily available around here, but I definitely see the difference in kitty litter and Oil-Dri, both obtained from Walmart.


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## Michael (Jul 20, 2010)

GadgetGirl, do you know what Oil-Dri is made from? It may be a different kind of clay than STS.


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## GadgetGirl (Sep 25, 2013)

Michael said:


> GadgetGirl, do you know what Oil-Dri is made from? It may be a different kind of clay than STS.


Could be. 
Bentonite (calcium montmorillonite)


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## Michael (Jul 20, 2010)

Thanks! STS is similar, if not identical.


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## Rockfella (Sep 7, 2021)

Old time STS/OilDri users have you ever tried Turface MVP?
TIA.


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## Michael (Jul 20, 2010)

My longest running tank (11 years) was set up with a "charcoal" Turface cap over soil. It is still growing healthy plants and fish. If I could get the dark gray color, I would definitley use it again. But all that is available by the bag here is an ugly red.


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## johnwesley0 (Feb 23, 2021)

I have a STS lining on the bottom of my 30 gallon long as well as a 1 inch cap. My object is to actually take advantage of its sand-like qualities as it breaks down over time to create anaerobic areas within the potting mix. There's a theory that it rejuvenates the soil.


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## FernKing (4 mo ago)

aquabillpers said:


> I recently decide to try Saf-T-Sorb in place of the soil substrate in an NPT. From what I'd read it offers a number of advantages, so I bought a lifetime supply for $7.
> 
> I rinsed it several times over a week. I remember thinking that it was very "dirty". The rinse water never really got clear but I added about an inch of the STS to a 10 gallon tank anyway and filled the tank with well water.
> 
> ...


It’s not fully fired “vitreous” clay so maybe you got it too wet too soon? I’ve heard of people saying it dissolves over time, so your constant rinsing and agitation may have just made it into soup 🤔


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