View Full Version : Mixing finer sand with a coarser grade...

05/09/2000, 01:37 PM
I have a 90 gallon tank with 36lbs of Caribe Sea Special Grade reef sand. It is very coarse stuff and I do not like the look of it at all. Plus it does not stay clean looking like the finer grades do. After reading several threads and articles, including the SandBed Archive, I decided on going with a deep bed of like 3-4". I have gotten mixed opinions on what to do to achieve this. Some advise on me on removing ALL the special grade and starting from scratch with oolitic and live sand while others advise on just slowly adding the oooitic on top of the special grade and slowly mixing it in. The tank is 8 months old. The only thing I fear is losing alot of the life that has already made a home in the existing sand bed. I am willing to do whatever it takes to make this right so please do not worry about being polite about this.

05/09/2000, 01:56 PM
36 lbs. is not that much. I would slowly add the smaller stuff into the tank and mix it in. In my 90 I have 3-4 times that much sand and I have 3.5" sandbed. If you truly want the 4" sandbed it would seem you have just enough of the 2mm size (special reef grade) that Dr. Ron's recipe calls for. I raised my sandbed 1 month ago from 1/2"-2" (varied in sections) up to 3.5". I just added it right to the top. I have not seen much of a difference in life in the sand bed (still lots of pods running around). Probably killed a few things by burying them but the "pods" come back quickly. Add a few detrivore kits and livesand from different sources and you are on your way.......RR

05/09/2000, 01:57 PM
Whatever life is in your sandbed would be much happier with oolitic sand. I would if at all possible remove all of the rock and put as much sand in at once as you desire. I would add the new oolitic and then mix it up pretty well do evenly disperse the coarser grain. 36lbs couldn't provide much depth in a 90g so I doubt there would be a problem with anaerobic spots or gunk being released into the tank.

05/09/2000, 03:55 PM
Hey joeyz,
Ron discussed this very thing at the CMAS conference this past weekend here in DC. If I understood him correctly, he said it was fine to leave existing rock and sand in place, and just sprinkle in small amounts of the oolitic on top, doing a section at a time across the tank. The finer grains will work down (or rather the coarser ones get "floated up"). Takes time but is probably preferable to total excavation. Hope I got that right, am thinking about doing the same meself...!

05/09/2000, 05:44 PM
Ok guys here goes. Funny you should mention Dr. Ron because a few weeks ago I emailed him asking the same question and his reply was to remove ALL the sand in my tank because the special grade was too coarse.
He also recommended that I add oolitic sand and mix it up with some live sand as well.
I mentioned to him that I had a few bags of the home depot sand and he said it was perfect. I too have read all these formulas from him and his reply did not match with any of these articles. Oh boy! Now I am confused! hahahahaaa!!!!!!!!!!
Any comments about this?

05/10/2000, 03:41 PM
joeyz, the only "formula" that I ever say was 2 parts ESV oolitic and 1 part Caribasea Aragamax. I'm sure lots of formulas exist, but I think Ron basically believe only oolite is the way to go. He was pretty funny when i mentioned I had a certain amount of 2mm aragonite.. he said, "its a worthless as a bulls teet". However, I should mention that it was crawling with life... I didn't even know it. I couldn't remove the old substrate from the back corners. Within days I saw loads of wormtrails spreading from the corners in to the oolitic sand. Basically it was better than LS, and I'd recommend keeping at least 10 pounds of it unless your certain its dead. HTH

05/10/2000, 04:15 PM
You'll get a lot of opinions on this. If there is lots of life in the sand already it would be nice to keep it. Did you seed it with detritivores? However, if you really don't like the way the sand looks now and you leave it in then in a few months you might be wishing you'd removed it when you had the chance. The larger grains do tend to migrate up to the top with time. If you do leave it in, I wouldn't try to mix up the different types of sand, though. Just add the new stuff to the top, seed it with detritivores and let them do the mixing.
Good luck,

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05/10/2000, 05:06 PM
the only "formula" that I ever say was 2 parts ESV oolitic and 1 part Caribasea Aragamax.

Isn't ESV's oolitic and CaribeSea's Aragamax basically the same thing?

Anyway as far as there being alot of life in my sandbed, I cannot say. I never added a detritivore kit to it but I do see the occasion spagetti worm coming out during feedings. I also have loads of baby shrimps and pods in the tank too. I can't imagine that most of this could possibly live in this coarse sand. I am sure they would be much happier in the finer stuff.

Robert - I did add some HD sand on top of my special grade a month or two ago and special grade did come up to the top just like you said in your post.

05/10/2000, 05:40 PM
No, it's not. The grain size and distribution is different. According to Dr. Ron, it DOES matter.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by joeyz:
Isn't ESV's oolitic and CaribeSea's Aragamax basically the same thing?<HR></BLOCKQUOTE>

Peace - John

05/10/2000, 06:08 PM
Thank you JohnL, the grain size is indeed different. This is what Ron Shimek and Rob Toonen once said in a thread long, long ago. Its what I did, and its working great for me. I'm sure there are a million other ways of doing it.

It sounds like you have a good amount of life already in there, I'd definitely recommend keeping at least 10 pounds of your current substrate. Push it in the back if you're worried about looks. Its probably nicer looking than Florida LS anyway and cheaper.

05/10/2000, 09:03 PM
I would gather all the sand you have in the tank at this time to several differnt places in the tank and add the new sand to other areas. I am doing this to my tank because I think that the different in substrace will provide different type of enviroment for various type of fauna. I think the coarse grade rubble will be the prefer home for a different group of animals than the finer sand.

Minh Nguyen
Visit my reef at:

05/10/2000, 10:30 PM

Most of you are missing the forest for the trees. First, there is no final perfect number for percentages, like all things with reefs there are ranges.

Depending on the contexts...

Optimally, remove all the coarse stuff. One way to do that is to put some finer sand on it - about 1/2 inch at a time, until the bed is about 2 inches deep. The coarse stuff will gradually find its way to the top, where it can be removed with careful vacuuming or simply scooping.

I like oolitic sand. It is clean, the grains are rounded and the size distribution is good. But....

It ain't the only way to go. Any sand mix with a predominance of fines and very fines will work. From the descriptions the Home Depot stuff seems to fit pretty well. It has the decided advantage of being cheap. However, really, given the costs of stuff we put in our tanks, ESV's oolitic is a bargain.

Frankly, as far as the critters are concerned the substrate can be made of any material (I once investigated a very diverse community: 800 species and over 50,000 animals in a square meter. The substrate was 4% arsenic, 2% copper, 1% lead and other assorted metals by weight - it was slag from an arsenic smelter). The point being, if the sediment is predominantly reeeeeealllly fine stuff, the critters will thrive.

You want a mix of sand grain sizes with the majority in the very small and even smaller size fractions, but with a bit of smattering of larger sizes for diversity's sake. The absolute percentages are really immaterial, except you probably want less than 30 % to be greater that 0.250 mm in diameter.

The problem with most of the CaribSea mixes is a much too high a proportion of coarser stuff. They apparently are offering a new "oolitic" mix, but I have not seen it. If you use any of their mixes, you should be diluting it with a lot of fine stuff.

Now, in all of the various questions that are asked me, everybody wants to "save the life" in the coarse sand. Well, okay...

Personally, I would simply vacuum it all out and set up a fine sand bed - in one glorious afternoon of muck diving. Not a whole lot that finds a coarse sand/fine gravel bed attractive will even survive in a fine bed. You will have to seriously seed the fine bed, and frankly it is a whole lot less trouble to remove all the coarse stuff first. If you want to save the critters in it, lift the coarse stuff out to a bucket, then agitate it the bucket and pitch the sand, letting the critters collect in the bucket. Add the bucket contents to the newly set up fine sand bed.

If you get a lot of silt in the water, this is not a big deal. Any reef animal can withstand this, and can deal with it just fine. If they couldn't hurricanes would have wiped out reefs long ago.

Folks - everybody in this hobby seems to want a cook book approach. This ain't it. There is no perfect number to aspire to here - rather perfection is an over all mix that if you walked on it on a beach you would call "mud," but not gooey mud...

Cheers, Ron

05/10/2000, 11:46 PM

05/11/2000, 12:47 PM
Based on an e-mail from ESV, their grain size is 0.1-1.0 with a predominance in the 0.5 range. CaribSea's Sugar Sand is 0.2-1.2.
So, neither provides much of the 60% 0.05-0.1 that Rob Toonen suggests, or the 40% 0.125-0.25 and 25% 0.0625-0.125 that Ron suggests. Even realizing that these are ballpark recommendations that Ron and Rob provide, I don't know of any source that comes anywhere near them.


[This message has been edited by TAC (edited 05-11-2000).]

05/11/2000, 11:23 PM
Thanks for taking the time to post here Dr. Ron :)
Not sure which way I will go yet but it's good to have options........

05/13/2000, 10:13 AM
Well I decided to go ahead and mix the HD stuff in and not remove the old sand. I put in about 10 pounds or so today and I will continue to add until I reach at least 2" to start with. Then if I like it I will add more. From what I can see, the HD stuff mixed nicely with the special grade and created a pretty nice look.
I'll post again once everything is settle in.
Thanks for all your comments on this topic :)