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Discussion Starter · #1 ·
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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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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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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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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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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Discussion Starter · #7 ·
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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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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Discussion Starter · #10 ·
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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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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Discussion Starter · #13 ·
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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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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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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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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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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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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