Restarted tank

[Thunderkat]

I finally have my main tank set up and running again.

It has a 7" deep sand bed (its a 55 long aquarium) using the special grade aragonite for plenums. I guess I didn't do a good job cutting the screen because in the middle of that sandbed you can see a black ring around it where the mesh is, oh well, as long as it works.

I have a sump in there now, it looks perfect for growing macro algae in it too in addition to its sumply duties (half of the sump anyways, the other side doesn't look good for growing much of anything).

There is also a 18 gallon refugium attached to the sump and right now its half full of live rock.

I still have my bak pak dual pak on there for skimming and still have my Tunze on there too (that was a pain trying to put that in there with the new higher sand bed).

So far the only problems I have seen in the new tank are SEA SPIDERS. :(

All I have in the tank right now is the live rock and the sea spiders don't seem to be going through the strainer on my return pump.

I am thinking about just sticking a peppermint shrimp in my refugium and letting it go to town and have fun.

[Dozer]

Good luck this time around Thunder! Of course, often times good luck comes with good effort 8) . Sounds like you're putting together a nice new system.

I have one question. Why did you decide on a 7" sandbed? Do you like how it looks that deep or was there a biological reason? I'm just curious.

[Thunderkat]

Needed the super deep sand bed for setting up a tank using the plenum system.

I am not relying totally on the plenum though, also going to put a layer of activated carbon on the bottom to help with the filtration due to its surface area it should grow some good bacteria.

Going to grow macro algae too to keep the water clean.

I really like the plenum system because it gives me the kind of tank I have wanted, a long shallow tank (I will never own a high style tank :lol ).

[edge78041]

What is a plenum system? Just curious

[GaryP]

Basically a plenum is a cavity under the sand bed that provides an environment for denitrifying bacteria to thrive. They require an area of low oxygen and convert nitrate to nitrogen gases. If you are interested in learning more, do a web search for the "Jaubert system."

[akm]

It's where you put like egg crate covered with something to keep the sand from going through at the bottom off the tank so there is a layer of water under the sand. Am I right?

[akm]

Cool, I guess I was right.

[GaryP]

Hino,

Sounds good. Let us know if we can do anything to help.

[GaryP]

Here's a very good discussion of the pros and cons of a plenum system by a very well respected author.

http://www.ecosystemaquarium.com/Documents/JuabertRevisited_Winter1997.html

[Thunderkat]

After reading that article I am glad I didn't put all my eggs in one basket. I added that 18 gallon container that I plan on filling with live rock, right now it is only 1/3 full of live rock. After reading that article its time to completly fill that container with live rock :lol

The only problem I saw with that article is it says you need burrowing animals but in the jaubert system you have to put a screen down to keep stuff out of the bottom layer of sand. They can't both be right. That makes me wonder how deep burrowing critters can be found in ocean sand.

[GaryP]

Hino,

I'm confused. Do you have sand under the screen? Only water should be under the screen in a plenum. That's the purpose of the screen, to create an anoxic cavity under the sand bed.

The purpose of the burrowing critters is to turn the sand over and eat any detritus that accumulates there. The critters aren't going to penetrate through the screen. I have a sand sifting star I will give you if you want it.

[Thunderkat]

From the article I read you need two sets of screens. One set keeps sand from getting into the plenum area, the second screen covers the bottom 2 inches of sand to keep the digging and burrowing animals out of the bottom layer of sand.

The top of layer of sand is left free for the critters to burrow and play in.

[GaryP]

Well, the top layer is where the detritus and nutrients are going to accumulate. I see what they are talking about. They don't want the bottom layer of sand being oxygenated by the critters. I've never seen a plenum set up with two layers though. I doubt many critters are going to burrow that deep anyway, especially if there isn't any food down there.

[Thunderkat]

My Tunze is doing a good job of keeping the sand oxygenated. Every few days I have to go back and level out the sand.

I found the optimum place to put the Tunze to cause the minimum amount of sand blowing but it still makes a little sand dune that moves over a period of a few days.

I want to lower the amount of current caused by the Tunze but not cut it out completly. The only thing I can think of is either putting lots of rocks in the tank (not suppose to be done with jauber system) or putting lots of fake plants in there (highly ugly).

One idea I had is to get a stand to put on the sand to hold live rock on but I haven't seen anything I could use (the ones that were perfect were made of metal and I can't use that).

Anybody have any ideas on how to reduce current on the sand without covering up more than 30% of sand bed and without taking the pump out (or plugging it up)?

[GaryP]

You can use some plate LR resting on a few pieces of LR to create a base on which to stack your rockscape.

[alexwolf]

i think Felipe has some plate rock, pretty reasonably priced too.

[GaryP]

I know that Texas Todd did something very much like what I am describing in his 92 gal. corner and it looked awesome.