sandbed question

[drewster]

I currently have about 1 1/4 inches of crushed coral for a substrate. I am wanting to add a little more but possibly live sand this time. Can i just buy live sand and put it over the top of the crushed coral? How much live sand would it take to add an inch or two to a 55 gallon tank. This is a reef tank too. Please let me know what my options are. Thanks

 

[reptilicus]

Hi, depending on the grain size of your sand, you would probably want it at least 3' or so deep. If you get very small grain size, ie <0.5mm, then you can use a sandbed just over 2" and you should be fine. If I were you, I'd get this and then seed it with a small amount of live sand. Take out what you've got now, as coarser sediments generally trap detritus which can lead to system collapse further down the road. Also, even if you do it properly, you need a much deeper sand bed (ie 6" or so) if you are going use coarser sand. Smaller grain size can also support a much wider range of organisms.
Regards,
Tom

 

[krazzydart]

depending on what you want to do with your system, a couple of inches is fine. I have 3 types of sand and coral in my tank, each set up in a differant spot (like a beach,going to the crushed coral,black & pink sand) just buy the sand from the local pet shop... because if you have live rock the sand will turn live later,,, saving you som $$$$$$$$ I bought "live sand" for my mini-reef and nothing came from it..... good luck!!

 

[reptilicus]

Hi,
many people often say that you don't need live sand because your live rock will populate your live sand. For the most part, this is true. However, there are some critters which only live in sand, so live sand is the only way to introduce these creatures to your tank. While many people do have flourishing sand beds using this method, I opted for a seeding my sand bed with a small amount of live sand simply because this will provide a more natural system, and IMO the more natural the system the better.
Regards,
Tom

 

[kmr]

I don't keep a sand bed in my 55g tank. I have 20 lbs crushed coral and 20 lbs live sand. The substrate is only about 1.5 - 2 inches deep. I don't have any nitrates too. I have heard from LFS that a sand bed can have higher nitrate potential than a reef with no sand. They took sand out of some tanks over time and found just a slight drop in nitrates. I also have a book that suggests only 5mm or so of substrate. I don't know what to think of it. You can even have the bottom of the tank covered in star polyps and have no nitrates. I do think if you don't keep a sand bed you must have alot of LR something close to 2 lbs a gallon. I like the sand for cosmetic reasons. Then again I run a simple Berlin style setup and wanted to spend my money on LR instead of more sand and wet/dry. Anyway to achieve a 3 inch sand bed using .5mm sand you will need about 100+ lbs of sand. I would buy the 80 lbs dry sand and 20 lbs live stuff. Anyone else got a sand quanity for a 55g?

 

[reptilicus]

Hi,
I have a sand bed in my tank because to me it seems the best way to keep nitrates undetecable. However, there are some very, very good tanks that have no sand bed at all with nitrates still at 0, and yes the key does seem to be a large amount of live rock. The reason seems to be that the denitrifying anoxic areas present in the lower layers of the sand bed can now be found in the equivalent zones of live rock. After all, the original Berlin system was with no substrate (however live sand was not "discovered" yet). The key seems to lie not in whether you have a substrate or not but rather the key to sucess is to ensure you do not have a trickle/cannister or any other type of nitrate factories sometimes referred to as mechanical filteration.
Regards,
Tom