Changing out subsrate...

[mpcolson]

I'm thinking about switching out my Black Hawaiian Substrate to regular sand. It's a passing thought I have every time I look at the photos in this forum. It seems that the sandy tanks are so much brighter than mine I want to try to make the change.

Heres the rub, I keep asking myself these questions...

Do I have to tear the DT down completely to do this?
Will there be a new cycle if I do it?
Is there any benefit other than aesthetic to doing this?

I was thinking I could switch out the substrate in sections using a Plexiglas divider to cut out a chunk out the bed and do it in thirds to seed the new sand. It would mean I would have to redo my live rock again but I can set it back up pretty easily.

Also doing the sectional method I thought I would be minimizing any cycling. The new sand would be seeding from the existing sand/gravel and sump.

In the end I may have a small amount of the old black sand in the new but it would eventually work itself to the bottom of the substrate due to its weight. I would also be able to have Blennies that currently cannot sift the grains in my tank.

SOMEBODY TELL ME I'M CRAZY!!!:crazy:

[CarmieJo]

Sorry, I missed this earlier. The advantage of an aragonite sand bed is that it will buffer your tank! If you can do it in sections I think you would minimize any chance of a cycle.

[Amphibious]

In the end I may have a small amount of the old black sand in the new but it would eventually work itself to the bottom of the substrate due to its weight. I would also be able to have Blennies that currently cannot sift the grains in my tank.

SOMEBODY TELL ME I'M CRAZY!!!:crazy:
OK, your crazy! Seriously though, you could do it like Carmie said, in sections. I’d beg-to-differ with you on the black substrate ending on the bottom. I’m stating it will eventually be on top because the smaller finer sand will actually fall beneath the black and RAISE it up. But that’s a good thing because removing the last of the black is easy with a syphon hose.

Let us know how this switch goes.

Dick

[mpcolson]

OK, Dick...

Put your thinking cap on for a minute please, mine is broken.

My tank is 36L x 18D how many pounds of sand do I need to make a 3" DSB? I believe thats required for a reef tank so anemones can set their feet etc.

I am looking at Marco Rocks Bahama Sand ( I know you are a proponent of that product ) and I think I used about 120# of this Hawaiian stuff, does the finer grit mean I need to use more weight to achieve the same depth?

[CarmieJo]

Matt, from what I remember of seeing Marc's sand at MACNA I'd consider it a "regular" grain size so you will need about 80#. You would go up to 100 if it was sugar fine. However, I think you are getting a BTA and in my experience they put their foot on a rock not in the sand. I wouldn't recommend 3" of sand, it is neither a shallow sand bed of <2" nor a deep sand bed of >4" of sand.

Send me your email and I will email you an Excel sand bed calculator I used for the calculations.