2 inches of sand?

[tdubrow]

I have my 75 gallon FO tank cycleing right now. I used 80 pounds of Caribsea fiji pink sand so it gives me about 2 inches of sand. A tad bit more in a few places. Is this too much sand?

Ive never had a problem with this much sand in my freshwater tanks but this is my first saltwater and I just want to make sure.

[Stuart60611]

IMO, it is too much sand. Others may disagree. But in a fowlr, in particular, with little to no clean up crew, the sandbed can often be a trap for gunk. That is why many people elect to go bare bottom. I do not like the look of a bare bottom tank, and therefore, I maintain a 1/4 to 1/2 inch sandbed. Anything deeper can start to be a nutrient trap. My sandbed stays very clean despite my heavy stocking, messy eaters, and no clean up crew.

[Stuart60611]

You can see how clean my sandbed is after close to two years below. I never stir, nor siphon the sandbed.

http://www.reefcentral.com/forums/showthread.php?t=1756144

[mattsilvester]

IMHO - with sand you should either go for a proper DSB...... less than 1/2"...... or not at all....... anything in between is in the no-mans ground of "maybe"......

I am of the BB persuation however ;)

[johno4]

It is not enough sand to really cause any problems. This is one of those things that is really a personal opinion.

[mattsilvester]

It is not enough sand to really cause any problems. This is one of those things that is really a personal opinion.

Truthfully, I beg to differ....... I had about 1 to 2" in my tank previsouly...... it eventually went black and stagnant and acted as a nutrient sink...... not deep enough to become a "DSB" and too deep to be areated properly by water flow alone above the bed......

But as you say Johno - this really is a matter of opinion..... at 2" it is just too much in no mans ground, in my opinion..... if it was 3 to 4" OR 1/2 to 1" then maybe......

[tdubrow]

I plan on doing weekly water changes while siphoning the sand which I have always done on my african tanks. I also stir up the sand to aerate it as well. Is this not a good idea? Isn't there sand sifting snails and hermit crabs that could work as well?

Its always been fine with my freshwater tanks but I'm new to the saltwater so it may be completely different. I can always get some sand out of there but if its not needed I'd hate to do it. I like how it looks :)

[johno4]

As long as you siphon like you mentioned you shouldnt have any problems.

[Stuart60611]

I totally agree with Matt from my personal experience and believe that impropper sandbed height can really cause substantial problems down the road. When I had another tank (RSM) and a sandbed of about 2 inches it eventually got dark also and became a nutrient trap causing parameter issues and resulting severe hair algae problems. I think you either have to have enough of a sandbed to properly operate as a DSB for denitrification purposes or no to a very shallow sandbed which traps little to no detrus. Anything in between is destined to cause problems because it will just trap substantial waste but not operate effectively at breaking it down.

[tdubrow]

For those of you who had your sand become a nutrient trap, did you siphon the sand regularly? Did you have a cuc?

I'm definitely not trying to be a pain in the butt here I'm just trying to understand why the 2 inches of sand becomes a problem.

Is there a major difference with 2 inches of sand in a freshwater tank as opposed to a saltwater tank?

Ive never had a problem with sand in my overstocked african mbuna tanks and those fish are messy. My bio-load in this saltwater tank wont even be close to that.

Ive been siphoning my sand weekly for the last 12 years and I dont see that changing any time soon.

[Stuart60611]

When I had a 2 inch sandbed in my old 34 gallon red sea max, I did siphon the sandbed with each water change which occurred bi-weekly and did have a clean up crew because it was a reef system. I really cannot make any comparison to freshwater b/c I have no experience in such a system. However, I am confident when I state that the reason a 2 inch sandbed is a bad idea is that saltwater tanks produce a lot of organic waste and detrus which gets caught up in the sandbed, if of any significant depth. Now if you have a deep sandbed (I think at least 4 inches) then the sandbed itself can break down this gunk through the denitrification process. If not, then the gunk in the sandbed decomposes and dispurses into the water column leaving the bacteria on your rock to break it down. The result is an increase in the waste in the water column and therefore adds to your bioload. The sandbed itself becomes a source of nutrients leaching into the system which is counterproductive and can create serious problems in terms of algae issues and high nitrates. A very shallow or no sandbed does not have the ability to trap gunk and therefore the undecomposed waste remains in the water column to be skimmed out and/or broken down by the rock which it ultimately settles upon. I hope this makes scense.

My prior RSM system ran great for about 6 months and then I had major algae problems. I went nuts trying to figure out what was happening and tried all of the traditional remedies without success. I ultimately sold the system. However, when I started to break down the system for sale I could not believe the amount of black organic matter trapped in the sandbed. At this point, I realized why I had such severe algae problems that I could not cure. Under the top thin layer, the remaining sandbed was black and filled with gunk which turned my entire water column dark black once I began to remove the sand.

If it were me, I would reduce your sandbed to 1/4 to 1/2 inch and keep the excess sand to later add as necessary to the system to maintain this depth. Asthetically, you really give up nothing doing so, but I believe you will have a much cleaner system, particularly if you are operating as a fowlr.

[LisaD]

I agree. My best success has been in bare bottom or shallow sand bed tanks. I don't know why, but deeper sand beds (especially 4-8") have been a problem over time. The shallow sand beds have stayed very clean, and haven't required a lot of siphoning. I have several tanks, and most have been set up at least 3-6 years.