# Coal Slag as substrate?



## Manofcichlids (Feb 5, 2006)

I have a 75g planted tank at home and have all the special substrates. 2" of flourite and eco-complete, 2" of gravel...all the common stuff...but a buddy of mine just used coal slag in his tank and his plants are growing better than mine...and I add ferts...he doesn't! Upon research, this stuff is made primarily with potash and contains an abundance of minerals.

I have a whole bag of this stuff and was thinking of doing about an inch of it on my new 90g with another inch of flourite and then my gravel. What do you think?

Why are his plants growing better? ...I have at least 4x more lighting as well!


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## mrbelvedere (Nov 15, 2005)

Well the nutrients could be a plus, but they might be hard to control, resulting in algae blooms.


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## Manofcichlids (Feb 5, 2006)

Stragely enough he doesn't have any algae. The gravel over it seems to control the nutrients from escaping, but the roots can dig down and use them as needed.

Anyone see anything wrong with trying this method out? Is it bad to have a very fine substrate at the very bottom of your 5" substrate?


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## toofazt (Jun 18, 2005)

I don't see anything wrong with a fine layer on the bottom. If it is real fine like play sand, it may cause anaerobic pockets of hydrogen sulfide gas, but if it is like pool filter sand then you shouldn't have a problem. Even if you put it on top of your substrate it would eventually end up on the bottom because it is a smaller grain than everything else.


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## Manofcichlids (Feb 5, 2006)

It is really quite fine...is there anything wrong with anaerobic pockets of hydrogen sulfide gasses? I know this occurs naturally in nature...saltwater people also use very fine substrate to get these gasses...explain?


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## toofazt (Jun 18, 2005)

Anaerobic pockets are toxic to fish. I don't know much about saltwater tanks. But I think the reason it doesn't happen in marine tanks is because there are 'things' that live in the sand that stir it up and move it around so the anaerobic pockets of hydrogen sulfide gas don't get time to build up.


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## Manofcichlids (Feb 5, 2006)

Would trumpet snails along with red ramshorns fix this problem? That's currently what I have in my other planted tank and the trumpets seem to mix it up quite fine.

Could I do all coal slag? I kinda like the thought of having a solid black substrate, or would it be wise to mix it with flourite and gravel on top?


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## Oqsy (Jul 3, 2004)

from my understanding, "black beauty" is a coal slag that's used in aquaria quite often. some aren't too fond of it because of it's rough edges (especially for bottom foragers like loaches and cories), but it looks pretty good, and is used alone as a substrate all the time. just make sure you rinse rinse rinse rinse. the trumpet snails should help keep it stirred up. there are plenty of people that use plain sand substrates (usually larger grain, but i digress) and supplement with either root ferts or water column dosing. i think the key here is going to be CO2, however. if you don't have it, consider flourish excel or diy yeast bottles until you decide you're ready to invest in a pressurized system. substrate nutrition can be overrated i think, in high light tanks anyway... (low light tanks are another animal altogether, and a "natural" substrate, ie "rich" is much more essential) find something attractive that holds the plants in place, allows the roots to spread, and take care of the ferts with root tabs or column dosing. perhaps the problem is too much light in your setup? if your ferts and co2 don't match your lighting level, then you're doomed to plants that get taken over by algae or rot from deficiencies. just throwing more light at a tank alone won't fix the problem, nor will simply putting in a new substrate. read carefully, www.rexgrigg.com , etc. and make sure you're balancing all the factors.

Oqsy


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## Momotaro (Feb 21, 2003)

> some aren't too fond of it because of it's rough edges


I think that would be my concern. I would be worried the substrate particles themselves would be too sharp and possibly do some harm to bottom dwelling fish.

Mike


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## Manofcichlids (Feb 5, 2006)

Well, I do have a pressurized CO2 system with Ph controller and everything. The lighting in my 75g is really not that much, 120w so I'm actually still pretty low but still lower per gallon than my buddy. I dose dry ferts from gregwatson.com and use the calculator to determine how much to add.

If I do go with the coal slag, since I don't put fish in the tanks, how thick do I want it and should I mix some dry ferts in with it or just use the tabs? I really like the thought of the black substrate...now just making it happen!


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