Sand bed questions
- Thread starter twilson
- Start date
Geodriller
New member
it is bad to stir a DSB not a SSB. bacteria deep in the sand bed use up all availabe oxygen called the anoxic zone. this anoxic bacteria will start to ''feed'' on nitrate instead of oxygen. If they contact oxygen after this the bacteria will die and pollute the water. If you stir the whole sand bed and kill alot of bacteria it will be bad for the tank and in extreme circumstances be detrimental. (little more too it than that, but that is the jist of it)
A DSB should be atleast 4''deep. (depending on grade). sugar fine sand would not have to be quite as deep as a more course sand.
SSB (Shallow Sand Bed) should be stirred once a week.
depth of sand has nothing to do with tank size. You should either pick one or the other and not lerk in the middle. either 4 or more inches or 1.5 or less inches.
There is alot of controversy between DSB & SSB. The biggest problem is after a couple years if a dsb is not taken care of it will become exhausted. But IMO a properly maintained DSB is good for a reef. I used a DSB of almost five inches in my 75 before I moved it for almost five years and never showed a reading on multiple nitrate tests.
A DSB should be atleast 4''deep. (depending on grade). sugar fine sand would not have to be quite as deep as a more course sand.
SSB (Shallow Sand Bed) should be stirred once a week.
depth of sand has nothing to do with tank size. You should either pick one or the other and not lerk in the middle. either 4 or more inches or 1.5 or less inches.
There is alot of controversy between DSB & SSB. The biggest problem is after a couple years if a dsb is not taken care of it will become exhausted. But IMO a properly maintained DSB is good for a reef. I used a DSB of almost five inches in my 75 before I moved it for almost five years and never showed a reading on multiple nitrate tests.
thecoralreefer
New member
So if you can't stir a dsb then what do you do to care for it ???
thecoralreefer
New member
Oh you mean like spaghetti worms and sand stars and necs snails And some pods too hohooo
thecoralreefer
New member
Oh and my fave for the top of the sand V Sexgutatta !!!!
You'd better be talking about Gobies. 
Well done answer Geodriller. The one thing about the anoxic zone is that it has low dissolved oxygen but plenty of nitrate present. The oxygen in the nitrate is used for metabolism rather than straight oxygen. That releases nitrogen gas. It takes awhile for the proper conditions to develop which are an oxygen level under 0.5 and at least some form of organic carbon present. The carbon is what the bacteria will consume when they use the nitrate oxygen.
It the bed is stirred the bacteria don't die (they are actually aerobic bacteria that have learned the trick of using nitrate's oxygen to survive) but it takes days to a week or two for condition to return to true anoxic. Hope that helps.
Well done answer Geodriller. The one thing about the anoxic zone is that it has low dissolved oxygen but plenty of nitrate present. The oxygen in the nitrate is used for metabolism rather than straight oxygen. That releases nitrogen gas. It takes awhile for the proper conditions to develop which are an oxygen level under 0.5 and at least some form of organic carbon present. The carbon is what the bacteria will consume when they use the nitrate oxygen.
It the bed is stirred the bacteria don't die (they are actually aerobic bacteria that have learned the trick of using nitrate's oxygen to survive) but it takes days to a week or two for condition to return to true anoxic. Hope that helps.
Geodriller
New member
Not sure if I understand. Do you mean have a remote DSB, aswell as a DSB in the fuge or, are you refering to the fuge as the remote DSB?
As far as 1-2 inches in the tank, your good. definitly no deeper than 2''. If you have a big enough fuge you can put the DSB in there. If you fuge area will not serve as a big enough footprint, you can just go with the remote DSB. Remote DSB's are becoming pretty popular. It makes it easy in case you ever have to change your sand out. How big will the fuge be?
The crushed coral may not be the right thing. If it is pretty big you may want to go with sand substrate for the DSB.
Geodriller
New member
Waterkeeper, thank you for the correction, and sorry for the misinfo. So the problem people have with stirring DSB is not actualy more "pollution" in the water from dying bacteria, but rather the inability for that bacteria to consume nitrate, thus the nitrate level rises.?.
Geo you did very well with your explanation. I wish more people understood a DSB as well as you do. The correction was just minor and really makes no difference in the advise you gave.
:thumbsup:
Wilson you really want sand as fine as granular sugar or finer.
:thumbsup:
Wilson you really want sand as fine as granular sugar or finer.
Geodriller
New member
Sugar fine is exactly what I was going to recommend.
If the crushed coral is in fact that small it will be fine, you will just have to make it deeper say 6''+. I could not answer for sure if 7g tank would be big enough. It is probably skating on the border. Is the 7g already set up and in use? If not then you should go bigger.
Also it really depends on what you want out of your fuge. If you want denitrification and nothing else, or very little else, then a 7g may work. If you want a DSB, macro, LR, and an actuall "refugium" for all the little critters, then I would go with a bigger tank.
I have a 75g DT w/ a 30g fuge. (just a big section of a 55g I made into a sump/fuge). It has 3'' of sugar fine sand (for denitrification) under 4'' of aragonite (mostly for pods). And I still have room. It has a footprint of 30''x12'' and I have seen 0ppm nitrate for years. I should mention I have a pretty big bio-load and crappy skimmer.
So basicaly if you are not commited to the 7g, I would go bigger.
If the crushed coral is in fact that small it will be fine, you will just have to make it deeper say 6''+. I could not answer for sure if 7g tank would be big enough. It is probably skating on the border. Is the 7g already set up and in use? If not then you should go bigger.
Also it really depends on what you want out of your fuge. If you want denitrification and nothing else, or very little else, then a 7g may work. If you want a DSB, macro, LR, and an actuall "refugium" for all the little critters, then I would go with a bigger tank.
I have a 75g DT w/ a 30g fuge. (just a big section of a 55g I made into a sump/fuge). It has 3'' of sugar fine sand (for denitrification) under 4'' of aragonite (mostly for pods). And I still have room. It has a footprint of 30''x12'' and I have seen 0ppm nitrate for years. I should mention I have a pretty big bio-load and crappy skimmer.
So basicaly if you are not commited to the 7g, I would go bigger.
MeReefBeef
New member
wait are you serious guys....I have a nano reef, if i have a SSB, i have to stir it every week? Otherwise, I need 4 inches of sand?! WOW! I have pretty coarse sand in there.....and its like 2.5 inches think >.<
