Crushed coral

[sassyfrassy]

Does anyone use CC in their DT anymore - or is sand better, and why. I'm not talking DSB - 1/2 to 1" of substrate.

[mdntrdr]

I just transfered my 50G. reef with CC to my 220G. with sand.

Never had a problem with the CC in the 5yrs. it was running.

[der_wille_zur_macht]

Crushed coral is just different from sand, it's not inherently better or worse. It gets a bad rep these days as a detritus trap and "nitrate factory" but IMHO these ideas are based on misunderstanding and point of view, not solid fact.

It's totally OK to use if you like it, or want it for a specific purpose. Keep in mind though that if you run your tank on the dirtier side, it will collect garbage (as sand will too, though it's more apparent with crushed coral). However, IMHO, this "disadvantage" is outweighed by the fact that crushed coral is much easier to vacuum during water changes, without sucking it out of the tank.

[Michael]

it can buffer ph as well imo, however it does get dirty and will give you problems if its too deep and not cleaned regually.

[der_wille_zur_macht]

The contribution of crushed coral (or any other substrate) to pH, alkalinity, calcium, etc. is debatable at best IMHO. It is true that you could dissolve any calcium carbonate-based material in acidic water to buffer a tank (this is what a Ca reactor is based on) but in order to contribute a significant amount, the pH would have to be pretty low to begin with, otherwise the material won't dissolve. pH in an average tank is probably several full points too high for this to occur. This is especially unlikely with crushed coral, since water circulation tends to be much better in the substrate than with sand. There are some data to suggest that the pH might get low enough near the bottom of a very thick deep sandbed, but IME it's still a minor contributor, and you're better off dealing with pH through conventional means (which are easy and proven) rather than trying to count on substrate choice to help you.

[Toddrtrex]

I used to use CC, but pulled it a couple of years ago after using it for 5-6 years. For the most part it isn't all that bad, but it does take some extra work, and not all fish/inverts like it. When I had mine (( shallow )) I "gravel vaced" it with each weekly water change. The amount of detritus that was sucked up each week was shocking.

[der_wille_zur_macht]

Originally Posted by Toddrtrex

The amount of detritus that was sucked up each week was shocking.

What most people don't think about is that even though sand won't trap detritus quite as readily, it's almost impossible to get out, so it pretty much stays there until it breaks down. At least with crushed coral you have the opportunity to vacuum it out easily.

Though, there are also debates that vacuuming can remove beneficial micro-life form your substrate (bacteria, pods, etc) so again, it depends on your approach and your goals with the tank - it's not 100% clear that one substrate is best in all situations.

[wooden_reefer]

Originally Posted by sassyfrassy

Does anyone use CC in their DT anymore - or is sand better, and why. I'm not talking DSB - 1/2 to 1" of substrate.

I use well cycled CC in DT only as a transition if I want to boost nitrification in the DT in anticipation for added sizeable bioload. I then remove it very slowly.

[Toddrtrex]

Originally Posted by der_wille_zur_macht

What most people don't think about is that even though sand won't trap detritus quite as readily, it's almost impossible to get out, so it pretty much stays there until it breaks down. At least with crushed coral you have the opportunity to vacuum it out easily.

Though, there are also debates that vacuuming can remove beneficial micro-life form your substrate (bacteria, pods, etc) so again, it depends on your approach and your goals with the tank - it's not 100% clear that one substrate is best in all situations.

I have had good luck with vacuuming my sand bed -- takes some practice to get the suction right -- enough to pull the detritus out, but not so much that it pulls all the sand out. I still see a decent amount of life on/in my sandbed, but my main two uses for the sandbed are looks and to keep my Haddonis happy.

[Michael]

Originally Posted by der_wille_zur_macht

The contribution of crushed coral (or any other substrate) to pH, alkalinity, calcium, etc. is debatable at best IMHO. It is true that you could dissolve any calcium carbonate-based material in acidic water to buffer a tank (this is what a Ca reactor is based on) but in order to contribute a significant amount, the pH would have to be pretty low to begin with, otherwise the material won't dissolve. pH in an average tank is probably several full points too high for this to occur. This is especially unlikely with crushed coral, since water circulation tends to be much better in the substrate than with sand. There are some data to suggest that the pH might get low enough near the bottom of a very thick deep sandbed, but IME it's still a minor contributor, and you're better off dealing with pH through conventional means (which are easy and proven) rather than trying to count on substrate choice to help you.

totally agree with you, i wouldnt consider cc to buffer ph, just stating it could do so, although obviously not much.

[sharrison]

one is not better than the other. I would pick substrate size based on closed loop output placement or power head placement. the bigger the substrate the less chance it will blow around. People ask baout what substrate to use, why not go BB with black starboard.
On the 180 that im putting together right now Im going to suspend black eggcrate from the bottom of the tank about an inch with either PVC or clear plexiglass rods and put all of my aquascape on top of that. In doing this I can run 2 of my black Loc-Lines lines down from the back side of my DT tank from my closed loop system on either side of the tank and have them both pointing at a 45 degree angle to the front glass. and there will be no dead spots anywhere.
That is the most important thing. (No dead spots). what does substrate create? (a lot of dead space)

[sassyfrassy]

Thanks everyone. I wasn't using it for any buffering qualities it may or may not have - basically I was using it because I could vacuum it easier to keep the tank clean. Within a month or so I hope to have a 30g refugium w/DSB. Although Frankly I'm confused about substrate and lights.