DSB concrete blocks

viper357

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Perhaps someone could elaborate on why a DSB made up of aragonite (in this instance, Aquamedic aragonite) would end up turning solid, as you can see by the pics, this person's DSB had to be literally smashed with a screwdriver to remove it from the tank, it came out in solid blocks, needless to say this DSB was not performing at all.

What causes this and what can we do to prevent it?

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Kanga

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Could I use a stainless steel skewer to see if mine is doing this
 

viper357

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I'm sure you could, or even a wooden kebab stick will do. I was really shocked when I saw this, solid blocks coming out of the tank, and I mean solid, we had to use a lot of force to break it up.
 
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jacquesb

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Hi Dean - this is usually due to a very high alkalinity being the standard over quite a few years of running the tank. Also, a shortage of micro-critters to "stir up" the DSB and create tiny "worm holes" etc in the DSB could also be the cause of this.....
As such - do I teem a DSB like that worthless, unfortunately....

I think that this would be yet another reason why micro-critters is so important, and perhaps "sand-stirrers".....

I run my alkalinity high, so I have to constantly check my DSB (in-tank as well as in-sump). BUT, one does not want to disturb your DSB otherwise it loses it's effectiveness as well.
 

Kanga

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I'm sure you could, or even a wooden kebab stick will do. I was really shocked when I saw this, solid blocks coming out of the tank, and I mean solid, we had to use a lot of force to break it up.
I have the same mixed with SeaSand, and not hard patches
 

Kanga

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Jacques, lots of life. dkh round 8-9 on avg
 
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this is disturbing, especially because of the price of aragonite......... :scared:
 

jacquesb

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Thanks, Mekaeel!

Thanks Kanga....

Dean - could you get this guys alkalinity measurements as well?

Another question - how much and how often do you guys dose ANYTHING (from baking soda, to commercial preparations) to increase alkalinity?
 
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Be careful with the white powder

Substrate clumps for two reasons:
As bacteria go about their business, they secrete substances which binds substrate grains together. This is more like a loose sticky clumping, easily overcome through bioturbation by microlife in th sandbed. (simple raking of a dsb is sufficient at this IMHO) This clumping is however nowhere near enough to form solid bricks.

Solid brick like concrete blocks are generally formed by precipitation of calciumcarbonate because of high temperatures, overshooting pH or overdosing of either calcium or alkalinity.

For a good read:

Greenfield Kalkwasser

http://www.reefs.org/library/aquarium_net/0797/0797_4.html
 

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