# A cautionary word about "biologically active" substrates.



## ukamikazu (Jun 4, 2010)

You have seem them online or in your favorite LFS: Substrates that claim to make the cycling and maturing time of your new aquarium happen instantly. They are especially popular with substrates that many of us rely on for planted aquaria but let's be honest with ourselves, we never believed it. We usually get the stuff because it's already rinsed which takes a lot of the headache and back breaking labor out of setting up a new tank. Generally speaking it's good stuff: A porous clay with laterite or other source of iron that has a high cation exchange ratio. All really anyone really needs, right? Simple, basic, grows plants, good enough. Everybody's happy.

As natural philosophers we all know that to keep the ammonia oxidizing bacteria alive they need food, the aforementioned ammonia, and oxygen preferably in solution, water. How, pray tell, can that biological reaction be kept going in a sealed bag that sits on a shelf in a warehouse for probably months on end? Well, it doesn't. It can't.

Most of the bacteria die, some enter cryptobiosis. Some bags can be pretty foul. You may have run into them, they look like someone poured a cup of milk in them, but I say there is still gold in them thar bags! A green gold called Ammonium.

As a humane, ethical fishkeeper and horticultural enthusiast, I abhor the idea of using live fish to kick start the biological cycle. It is unnecessarily cruel. I have always used the fishless method. Before, I would use pure ammonia from the hardware store which is a lot less nasty than just tossing in some rancid shrimp, but to each his own as long as ammonia is being consistently fed, it's all good.

Then I discovered ADA Aqua Soil. This stuff is the bomb for growing plants especially if you use the complete system, Power Sand below and the Aqua Soil itself on top. And it releases a ton of ammonium, preferred by plants which gets everything into high gear. The bacteria get a great start, the plants grow like mad and in 5-6 weeks, you do a large water change and it's ready for fish. Simple, easy, effective. No measuring ammonia and testing from a bottle every few days to make sure the reaction continues until the tank matures. There's enough in it to keep it going for the time necessary to get everything established. By now, everyone probably knows that Amazonia has the most amount of ammonium and Affricana the least. Here's a picture of a Tetra Ammonia test 24 hours after putting Africana in a new tank:










Here's the same vial, lit from below with a powerful LED flashlight:









Almost opaque, no? It's obviously off the scale and if I had to guess, I'd say 8 mg/L? After 6 weeks the water was perfect, the plants were lush and I could add fish. This is the normal time frame. Of course I tested for not only ammonia, but nitrite and nitrate weekly until what was left could be easily dispatched with a large water change and everything was good.

Again, this is most desirable as an aquatic gardener and ethical aquarist as well as convenient.

Now, why am I telling you things you already know? I want to give you a little caution about the other more common rocky, gravelly substrates we all know and love that claim to be biologically active and speed up the cycling of a new tank, a claim ADA doesn't make, thank goodness and likely never would have nor will.

First, the claim is bologna, as I mentioned above and we all know (suspect) why, as previously stated.

Second, while some components may still be there, you may have enough of a culture to get things started, but still no source of ammonia, especially if you have no intention of subjecting fish to an immature tank even if it is going to be heavily planted from the get go. You can still do it cruelty free if you stock lightly in the beginning but plant densely, it'll just take about 8 weeks, possibly more because the bacteria have to compete with the plants for what precious little ammonia there is and remember, plants preferentially absorb ammonium, then ammonia before they'll even touch nitrate. They'll take nitrite over nitrate even, so nitrate is their last resort in their search for nitrogen. I think you get the picture as to the interesting interactions that go on in a brand new aquarium and why it can be such a critical time.

Third, I love getting the old, fouled bags of Activ Flora and Eco Complete. These should be as valuable to us as light sweet crude oil but fortunately aren't as hard to find and extract. They are rich in ammonium and still have some viable populations of both nitrosofying and nitrifying bacteria. As much as I love Aqua Soil, these old bags are much more likely to be found at chain retail big box pet stores at heavily discounted rates. What with money being tight these days, this is what some of us must do. 
Also, in the interests of full disclosure, I must admit that uprooting a large swordplant or Cryptocorynes from Aqua Soil is a bit messy and sometimes the smell is a bit much for those members of your household that can't appreciate the odor of good earth. Personally, I wish Glade made a scented plug-in that smelled like potting soil or forest soil after a good rain. I'd like that more than their other frilly silliness.

Simple gravel is just easier to deal with especially if your tanks are more propagators rather than permanent display tanks. That's why I go back and forth between the two substrates. Aqua Soil in the stable, permanent display tanks, gravel in the ones that are always in flux and meant to serve as test beds and propagators.

This is where the cautionary statement comes in. Sometimes, you'll pay for a "fresh" bag that looks clean. It may not be. This happened to me last weekend as I was building a nano African biotope (more about that later). I read somewhere that PetCo was having crazy discounts on their planted stuff, so I went down to my nearest one, got two 16 poound bags for just under $20, exactly enough for a 10 gallon. I just planted the first few plants last night and tonight I decided to start testing to see where we were and to try and figure out how much ammonia I'd have to add. Apparently, not any. I'll let this picture speak for itself. Remember, other than some plants last night, nothing else alive has been added to this tank:










Ammonia/Ammonium 5 mg/L
Nitrite 1.6 mg/L
Nitrate 18.5 mg/L (best estimate)

Now imagine if I had added more ammonia without checking first? My plants would probably have gotten severe fertilizer burn and I would have crashed the population that appears to have already established itself. Or worse, if I had added fish or shrimp without testing at all to begin with!

Moral of the story:
1. Please attempt fishless cycles.
2. If you need to do something on the cheap, get a fouled bag of substrate.
3. Even if you do appear to have a fresh bag, test before you add animals. You just may be in for a surprise.
4. Just test your water regularly for goodness sake!

Thank you for your attention.


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## Diana K (Dec 20, 2007)

A lot of really good points. 
I have used the fishless cycle and it works really well, even if there are no sources of bacteria to jump start the cycle. The right bacteria seem to find the tank pretty fast. 
If you are using a substrate that already comes with and produces more ammonia while it is adapting to life under water, then watch the nitrite levels. Some of the bacteria that we are trying to grow seem to stall when the nitrite is 5 ppm or higher. I would do enough water changes to keep the nitrite under 5 ppm. (Might only take one or two water changes mid cycle). The bacteria we are trying to grow need certain minerals. If the water is too soft they will slow their growth, or die. Make sure the GH and KH is over 3 German degrees of hardness.


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## ukamikazu (Jun 4, 2010)

Excellent reminders, Diana. Very good to remind us all of that. I also seem to recall that the bacteria that convert the Nitrite to Nitrate, the Nitrospira, tend to be rather delicate so again, very easy to crash ones population if one doesn't follow the guidelines you mentioned.

*I would also like to add a note to any new aquarists out there reading this: Do not add ammonia laden substrate to an already established, populated tank. Very bad things will happen.


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## Diana K (Dec 20, 2007)

Yes, there are a number of ways that the differences between these 2 groups of bacteria (ammonia removing types and nitrite removing types) behave in our tanks. 

In general the ammonia removing types are more tolerant of a wider range of conditions, and reproduce faster, so if something happens to the colony, they recover faster. 

The nitrite removing ones seem to grow slower. They do not handle cold so well. This can be a problem in the spring, in ponds. The fish are starting to be more active, but these bacteria are not keeping up with the rise in nitrite. The ammonia removing bacteria are doing their job (producing nitrite), but the nitrite removing ones are not up to speed yet. Golds and Koi can show Brown Blood Disease from the nitrite in the water. 

During the fishless cycle (aquarium or pond) the ammonia removing bacteria can grow to a big enough population that they can produce too much nitrite, too fast. The nitrite removing bacteria do not do so well with high nitrites.


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## aman74 (Nov 13, 2006)

ukamikazu said:


> I read somewhere that PetCo was having crazy discounts on their planted stuff, so I went down to my nearest one, got two 16 poound bags for just under $20, exactly enough for a 10 gallon.


How deep would the substrate be, 32lbs. seems like a lot for a 10 gallon, but I haven't set up a new tank in a long time.

Thanks for your post as well!


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## ukamikazu (Jun 4, 2010)

aman74 said:


> How deep would the substrate be, 32lbs. seems like a lot for a 10 gallon, but I haven't set up a new tank in a long time.
> 
> Thanks for your post as well!


You're more than welcome.

It actually came in right at 3 inches, amazingly enough. I didn't expect that seeing as how chunky the Activ Flora is. I thought one bag would have done it, but no, two was exactly right.

The plants are rooting through it just fine, too. Still, I don't think I'll be buying any more of that brand. Not burrower friendly and planting can be difficult because of the rather large size of the very jagged pieces.


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## aman74 (Nov 13, 2006)

ukamikazu said:


> You're more than welcome.
> 
> It actually came in right at 3 inches, amazingly enough. I didn't expect that seeing as how chunky the Activ Flora is. I thought one bag would have done it, but no, two was exactly right.
> 
> The plants are rooting through it just fine, too. Still, I don't think I'll be buying any more of that brand. Not burrower friendly and planting can be difficult because of the rather large size of the very jagged pieces.


Thanks, reminds me how expensive substrate can be, that's a chunk of change for a small tank. Gives me all the more incentive to try MTS with a CQ cap or similar.


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