Sandbed options?

[Rolo]

Hello everyone!
This is my first posting so I'm not sure if I am doing everything correctly.
Anyway, on to my question. I've been researching quite a bit on sandbeds, at least as best as I can now that I am a first time father to an adorable seven week old daughter. You fathers know what I'm talking about. She's definitely a greater time requirement than the aquarium.
I have a 90 FWLR and some of the easier corals. I am going to make a canopy to hold two 250 MH (maybe MV) and two VHO for actinics. Any DIY advice or plans would be appreciated for that too. I would like the canopy to be able to open from both sides because I have the aquarium in the middle of the room.
Back to my sandbed question. I came across this advice in this website, in the archives section. This person said the following:
"Ironically, the best defense against this problem is to stir sand BEFORE it is too late. That is why you need animals stirring and sifting sand. Otherwise you have to provide good diffusion through the sand layer. The third solution is to have thin sandbed."
Currently I have the third solution. I only have about 20 lbs of crush aragonite, about sesame sized grains in my tank. I was considering trying the thick sandbed option, say 4 inches. I've heard about people using some stuff from Home Depot called Southdown. I can't find any of that stuff here in Toronto, so I was wondering what alternatives there were. Can silica sand also work? Anything else? Or should I just stick with the current thin sandbed.
I have more to ask, but I've already made this too long, and baby is just starting to cry now.
Thank you for any advice.

[Rueg]

Hi Rolo. I bought my Southdown sand at http://www.shopreefland.com/ They have a picture of the bag on their site so you can see what it looks like.
You really need at least 4" for a deep sand bed to work. Being that I recently converted to one, I can say that they are a pain to convert to. Taking everything out of the tank and placing the correct sand in the tank was not fun. Everything is going good so far though as far as the sand bed goes. Sounds like your current grain size is too large. Are you having problems with Nitrates or anything? If it isn't broke, don't fix it. Unless you are like me and like to try the latest and greatest and like to create additional work for yourself.

[Crawdad1]

FYI : If you go with the Southdown sand get ready to have a tank that is cloudy for at least 1 - 2 weeks!! Its well worth the wait, but don't be surprised with the great white cloud.

[OodleyBoodely]

To combat that cloudiness after adding new sand, I used a tetra air powered sponge filter.. It does a great job of pulling dust particals out of the water. You still have the sediment to deal with, but you could stir it up and allow the sponge to do its work.
P.S. If you have any kind of power filter on the tank at this time, turn it off or the fine sand will get into the impeller chamber and destroy the impeller. I know from experience.

[Tadashi]

I also have my aquarium in the middle of the room. Look at my 155-gal for how I did this with and build the DIY hood. I would not keep the hood open with a young one around. It is not good for their young eyes to be able to look into a MH bulb. Too bright.

My hood is open at the top. I basically just push the hood back 6" to access the tank.

I added the new sand. Then placed a layer of LS on top to see it and to keep it from clouding up the tank. If you use a filter you will pull out the fine mud sediment that you want. That is why you do not wash the sand prior to adding it. My tank cleared up within 30 minutes.

I have nassarious, hermits, and lots of worms to stir my sandbed. Most will recommend for you to get rid of CC.