Substrate question

[Tmm87]

Hello,

New to the forums (and the hobby to a degree). I've been keeping freshwater tanks for 16 years now and only recently got into salt within the last year. My current tank is a 70 gallon FOWLR (I do have a couple zoas and a candy cane).

In a couple weeks I'm moving and will be upgrading to a 120 and was looking into a deep sand bed. Current tank has a 2 inch bed of CaribSea Hawaiian black which wasn't expensive to set up but with a DSB I'd be looking at somewhere in the 280-300+ lbs range for sand.

First off I'm looking for opinions on DSB vs SSB. I've done research and the idea behind the DSB is very appealing to me as it will allow for different types of fish as well as the denitrification aspect. My current shallow bed is easy to maintain, I have no issues with debris and detritus buildup. I know there are countless threads on this but I was hoping for some current info in case there were some articles/studies/etc that I may have overlooked.

Second question is grain size. What are your preferred sizes? I know CaribSea is limited in what they offer, but I'm sure there are other brands out there. I love the way the black looks in my tank now but contemplating swapping to a lighter color for the larger tank not only to mix things up as well as being told that lighter sands will reflect the light better and help with coral growth, etc. I know smaller grain is better for sand sifters such as a Diamond goby which I plan to add to the tank down the road but my fear is also snow storm from the power heads.

Third (and it ties into question #1), if I end up going with a DSB is there an option for a sand that won't get kicked up by the power heads that will still be relatively inexpensive? I'm not looking to go super cheap but I also don't want to shell out a full paycheck just to purchase the sand I need. Even with my discount at work I'd be looking at around $25 for a 20lb bag of CaribSea. In my searching I found lots of old posts about a bulk "Play Sand" made by a company called South Down, which then became Old Castle/Yard Right. These sands seem to no longer be aragonite and are all silica based. I know MarcoRocks sells bulk Oolite aragonite but everything I read on it leaves me hesitant to purchase. Most reviews said it was very messy and took forever to really settle and not get kicked around. Other places I found that had reasonable grain size were charging upwards of $2/lb not including shipping.

Thanks in advance for any information and replies.

[ycnibrc]

DSB eventually will give u problem. If you want sand then go shallow 1 inch

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[Michael Hoaster]

Assuming a small grain size sand, both deep and shallow sand beds wills give you denitrification, so depth is really up to you. How about a medium depth bed (MSB) of 2-3 inches? Also, adding some course substrate on top of the fine stuff provides a natural refuge for pods, and it limits the sand blowing around in the current. If you really want a fully functioning sand bed, be sure to seed it with quality live sand. Not just the stuff with bacteria, you want worms and other valuable detrivores.

To save cash on sand, you could reuse your old sand. Just put it on the bottom. The same goes for silica sand. Use these to add cheap bulk, then add the fancy, aragonite stuff on top.

Look for free shipping deals when ordering sand online. Otherwise, it's cheaper to buy it at a LFS.

[A sea K]

[welcome]
Not one to start a debate on SSB vs DSB but IMO a DSB will eventually become a nutrient sink and will present issues in the long run. With the current array of available reef equipment I see no need to use a DSB as their primary use as far as I know was to combat high nitrate levels.
If your needing a DSB to house specific sealife then thats another issue entirely.

[Tmm87]

Thanks for the replies, really appreciate it.

[heathlindner25]

If you have zoas and candy cane, it's not a Fowler.

[billdogg]

I have had both SSB and DSB's. If you want the benefits of a DSB without the risk of it becoming a problem down the road (which, btw, can be minimized by keeping it stocked with the appropriate organisms) I would suggest a remote DSB. If it does happen to become an issue, you can easily take it off line without disturbing the DT. In addition, you won't waste valuable real estate on sand.

When I had a 150DT with a 4' Undulated Moray, nitrates were a constant problem. So high that they really weren't testable unless I did a 75% water change, and then they would fall to 80-100ppm. Hair Algae? You have no idea what Hair Algae is!

I researched DSB's and their ability to fight high nitrates and so decided to give it a try. I used an old 120g tank as a remote DSB and filled it with ~#300 of sugar fine sand. I seeded it with a handful of CC from the eels tank and a piece or two of LR. Within 6 weeks or so, the nitrates began to fall, and within 3 months became nearly undetectable. The HA went away with no effort form me. Clearly, this shows that they can and do work.

IMHO, the problems occur for a couple of reasons. Either the DSB is not big enough to be effective, or the tank is stocked with creatures that eat the worms and other fauna that the DSB needs to work. Wrasses, crabs, sand sifting stars, etc are a huge issue in that regard.

When I set up my current 120g DT, I went with about 2-3 inches of fine sand throughout. I then allowed the power heads to do their jobs and let the sand go where it wanted to. This created areas (the back half) with what amounts to a DSB, and others (the front of the tank) with a very shallow sand bed. Not only does this make it look more natural (IMHO) I get the benefit of both, I can also still have the livestock I want.

hth

[jda]

I don't think that anybody has found any Southdown for more than a decade. Even when it was available, it was very, very fine and would blow around way too much.

You can order sand on the internet shipped in USPS flat rate boxes for fairly cheap. It has a mixed grain size, so it stays in place a bit better. Although I DO NOT recommend dry and dead from from them, the sand at someplace like Marco Rock is nice and inexpensive.

I am not a DSB guy, but I also will never have a tank without sand. DSBs failing a person is a result of poor husbandry where the aragonite binds up the phosphates that the reefer does not do a good enough of a job removing... eventually they cannot bind anymore and get blamed for "leeching phosphate" when in deed they don't leech anything, but have just stopped binding it. The other failure for DSB is when they get so bogged down with organics that they creatures in them cannot function anymore - they were never cleaned.
Dr. Ron used to love to suggest that nobody ever touch their DSB, but this was a mistake IMO and they should just rarely be touched and cleaned a little at a time. There are folks who have DSBs for over a decade with no issues. In nearly all cases, the sand was doing what the reefer wanted, it just stopped doing it when the accumulation of poor husbandry caught up to it. Bottom line is that people blame the sand rather than looking in the mirror - such is life, right?

I like a 3-4" sandbed. I vacuum it every so often after a few years about 20-25% at at time and waiting 2-3 months in between each section. I also start to replace it at about year four at about 20-25% a year so that I get it all by year eight. I keep a cuke (which are now four) a few conchs and the other myriad of creatures to keep it clean.

[Hal]

DSB's are controversial. Some people hate them, some love them. I'm in the latter camp. I've had a very fine particle DSB (Southdown actually) for years and never had a problem. I also like the idea of having a bed for certain species of fish to dig into.

I also run 3 MP40's in my 250g, so I have a pretty good amount of flow. Never a problem with kicking up sand. The only time anyone has issues here is if the powerhead is pointing at the sand.

If you are looking at removing nitrites, then yes, a shallow sand bed will do the job. If you want to remove nitrates, then you need a DSB for the anoxic zone. For removing nitrates, the smaller the grain size the better as you will more quickly create an anoxic zone as you go deeper into the sandbed. It also gives you more surface area at the top of the sandbed for other good bacteria to latch onto.

Personally, I don't think a DSB needs to have maintenance performed on it. Just set it and forget it. I also don't think it needs worms and other creatures to work. For me, a DSB is to remove nitrate. It does that by the bacteria that grows in the anoxic zone. No worms or bugs needed. If you're worried about keeping the top layer clean then get some nassarius snails or a diamond goby. But that's not anything to do with removing nitrate.

IMO, DSB's only have three problems. 1. it takes up vertical space in your tank; 2. you can have several inches of sand visible from the front which can show black blotches from the bacteria/gunk that is in the DSB in the anoxic zone; and 3. if you mistakenly stir or disrupt the sandbed in the anoxic zone you can release toxic gas (sulpher dioxide I think) into your water which can kill the fish. So don't stir the sand. Some people also claim that aragonite based sand provides some kind of buffer to the water, or otherwise contributes to the calcium or something. I'm not a chemistry guy and I haven't looked into it, so I don't know if that is true or not.

If you have doubts about the functionality or otherwise don't like the look of a DSB in your tank, the remote DSB is a great choice since it's easy to remove. I'm thinking about adding one to my existing in tank DSB.