# Seachem Onyx Sand



## Aj86 (Feb 26, 2005)

Hey everyone ive been scouting round the site and i think that ive come to solution that i need a rich substrate... When i started my tank i wasnt expecting to have alot of the plants but that soon changed lol now the question that i have is i dont really want to drain my whole tank and everything im jus wondering wether i would be able to mix the new substrate with the old that i have in my tank without having to take out anything.. Is it possible? 

The 3 substrates i was looking at was the seachem onyx sand or gravel http://www.aquariumsuppliesgalore.c...rium_Substrate_Seachem_Onyx_Sand_details.html the seachem flourite http://www.aquariumsuppliesgalore.c...nted_Aquarium_Substrate_Seachem_Flourite.html or the eco complete http://www.aquariumsuppliesgalore.c...Complete_Planted_Aquarium_Substrate_-_20.html would any of these be alright to use? Any advice would be awesome!

Thanx in advance!

Aj


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## aquaverde (Apr 15, 2003)

Onyx gravel grain size is too large for a planted tank. Any of the others will do you very well, but the Onyx sand will buffer the water. Occasionally, eco complete will do the same, but it shouldn't. There are some contamination issues with the eco. The contaminant grains will show as white in the tank.

My personal favorite is Onyx sand.


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## ceg4048 (Mar 26, 2004)

Aj,
All of the substrates you noted are fine to use, I don't think you can go wrong with any of them but the question is why bother adding more substrate to what's there already? You didn't really say exactly why you feel you need to add more substrate other than that you are getting many more plants. In my opinion that doen't really justify the trouble of adding more substrate. Why not just add more water column fertilization? Ultimately, the substrate runs out of steam in the long term and the plants find it easier to pull nutrients from the water anyway (even when they are fed at the roots). If I dose heavily I find that all the plants grow like gangbusters, even the so called heavy root feeders. I don't even bother with root tabs anymore, one less thing to buy.

On the other hand, I suppose if you are going low tech, no CO2 and less water column fertilization you probably ought to have a richer substrate, but that's about the only time it makes sense.

Cheers,


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## aquaverde (Apr 15, 2003)

That post reminds me. You won't be able to add anything but Eco-complete without draining the tank or doing a water change, and even with eco a water change is a good idea because of the "black water" packing eco comes in.

As far as "rich" substrates are concerned, I have a different definition for that anyway. I don't count any of these as rich. The benefit these products provide comes more from the porosity in their structure and how that relates to what happens at the plant roots.


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## Aj86 (Feb 26, 2005)

ceg4048 said:


> Aj,
> All of the substrates you noted are fine to use, I don't think you can go wrong with any of them but the question is why bother adding more substrate to what's there already? You didn't really say exactly why you feel you need to add more substrate other than that you are getting many more plants. In my opinion that doen't really justify the trouble of adding more substrate. Why not just add more water column fertilization? Ultimately, the substrate runs out of steam in the long term and the plants find it easier to pull nutrients from the water anyway (even when they are fed at the roots). If I dose heavily I find that all the plants grow like gangbusters, even the so called heavy root feeders. I don't even bother with root tabs anymore, one less thing to buy.
> 
> On the other hand, I suppose if you are going low tech, no CO2 and less water column fertilization you probably ought to have a richer substrate, but that's about the only time it makes sense.
> ...


Hey ceg the reason for me wanting to add the substrate is because at the moment i only have plain gravel and i have been reading through articles and they have said that it is a must to have a nutrient rich substrate mixed in the substrate... So i thought thats the way to go! My tank isnt very well lit its only 2.2wpg so you could say its a low tech tank but i do have a bit of CO2 running through it but my plants dont seem to be growing very much but i have been told that they bottomed out so yea... Do you think i may need it?


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## Aj86 (Feb 26, 2005)

aquaverde said:


> That post reminds me. You won't be able to add anything but Eco-complete without draining the tank or doing a water change, and even with eco a water change is a good idea because of the "black water" packing eco comes in.
> 
> As far as "rich" substrates are concerned, I have a different definition for that anyway. I don't count any of these as rich. The benefit these products provide comes more from the porosity in their structure and how that relates to what happens at the plant roots.



Aquaverde: I dont mind about doing a water change thats fine. About the rich substrate i just meant to write nutrient rich substrate lol sorry...


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## Anthony (Jan 11, 2005)

I like the onxy gravel mixed with the eco. The size is close to normal gravel but it is working great in my tank.


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## ceg4048 (Mar 26, 2004)

Aj86 said:


> Hey ceg the reason for me wanting to add the substrate is because at the moment i only have plain gravel and i have been reading through articles and they have said that it is a must to have a nutrient rich substrate mixed in the substrate... So i thought thats the way to go! My tank isnt very well lit its only 2.2wpg so you could say its a low tech tank but i do have a bit of CO2 running through it but my plants dont seem to be growing very much but i have been told that they bottomed out so yea... Do you think i may need it?


Hi Aj,
Well, 2.2 wpg with CO2 injection doesn't reall qualify as strictly "low" tech (I guess it would depend on your ppm). You know, if I see a growth slow down my first reaction is to add more PO4 and NO3 to the water column. I really doubt you could increase growth more by adding traces to the soil than to the water column. I mean, that's why they're called aquatic plants remember? The feeding mechanism for submerged plants is optimized for the water column. In fact, when you buy plants which were grown emersed and then throw them in the tank they go through the excercise of growing a new type of leaf specifically for submersion. Have you noticed that? When I first started growing plants I thought I had gotten gipped because the submersed forms didn't look anything like when I brought the plant home. Just think about it for a second, when the plants are in air it's easy to feed from the roots because of capillary action, hygroscopic behavior of water and evaporation. Submersed, this action is a lot more expensive. The plant has to use something similar to osmosis to pull nutrients up from the soil. This is not to say that it isn't done, just that it's expensive.

The "rich" substrates are typically rich in Fe, Ca, Mg and a few other traces, that's all. Again, I can add that directly to the water column, big deal.

When you're doing low tech, your light is less than/equal to 2wpg, you're not adding CO2, you're not changing the water nearly as often and you don't fertilize the water as much. In this case growth is a lot slower and root feeding is more relevant. The whole point of low tech is to slow growth and reduced maintenance such as trimming, water changes etc. But that's not really you goal I suspect. You _want_ more growth. The best way to achieve that is through water column fertilization. I don't think you posted your dosing regimen. Let's have a look at you dosing and interval and I'll bet dollars to donuts we can tweak it to improve growth.

Theoretically you ought to be able to grow just about any plant in plain sand - as long as you dose. What's great about the new dosing schemes such as EI and PPS is that they free you from substrate dependancy. I'm not slamming any of these products, it's just that you have an alternative. I would love to use onyx sand (it's not sold in my area) but not necessarily because it's so much better than brand "X", but only because it's dark grey and it would look really cool against the green plants.

Cheers,


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## plantbrain (Dec 15, 2003)

These substrates will help, but they are not a must.
I am willing to use anmd recommend them, they do help, but I did pretty well with plain sand and RFUG for a decade as well.

But it is a one time expense and makes things do a significant amoutn better from what I've seen.


Regards, 
Tom Barr


3rd annual Plant Fest July 8-14th 2005!
[email protected] Get connected
www.BarrReport.com Get the information


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