Deco Rock streams and sand

[jeffreywilens]

Since my 36" deep tank needs a lot of water movement in the bottom half, I am considering mounting two 6100 streams inside deco rocks at the bottom of the tank angling slightly upward.

I am a little concerned about keeping the sand out of the intakes as the intakes will be a very short distance over the top of the sand bed.

What is recommended in this scenario? Should the sand be removed where the rock is going to sit? If so, then the rock will be too low vis-a-vie the rest of the tank and will be firing right into the sand bed.

This is a 3" sand bed of sugar-sized aragonite. The tank is 96x30x36.

 

[rvitko]

Do not put the streams at the bottom. If sand gets in them the pumps will be destroyed. The rocks are not meant to go on the bottom, they shoud be on top of a rock structure, both for maintanence purposes and to keep debris out of the pumps, getting sand in them will absolutely destroy the pump. If you used the magnet holders and mounted them 24" from the bottom you would still have substantial bottom flow.

 

[jeffreywilens]

This is bad. I don't think the magnets will work. I have 3/4" thick acrylic and did not even see a magnet attachment that is being offered for that size. Even if there is one, this is a room divider pennisular tank and I really don't want any powerheads so obviously visible. That is why I bought the deco rocks.

A couple questions then.

1. Can I put the rock on a piece of acrylic sitting on the sand bed or just clear the sand out from under where the rock sits. I could then use some rocks to tilt the front end upward a little. How far away from the sand (in inches) would I need to be?

2. If that would not work, how should the deco rock be secured to rocks I already have in the tank. I have sort of an arch formation right now. Unfortunately, no really flat stones to rest it on. Might have to be wedged into a gap.

I must emphasize that I have a very long and tall tank. The returns are only on one side and the far side of the tank has very little water movement. Specifically the water scum is not being pushed back into the internal overflow with any kind of great effectiveness. Plus I have lots of cyno on the sandbed. It would best if I could be as low as possible and angle the flow upward and outward from the two distant corners of the tank.

 

[rvitko]

They should be at least 8" over the sand. Honestly I would place them on a 12" stack of rock. The flow from these pumps is 2ft around- you realize that their is a huge amount of movement from them so it really isn't an issue. I have had no problems building small structures of rock to stand the rock on.

Magnet holder 6200.50 is for 3/4" material.

 

[skippyreef]

is the same true with a BB tank Roger? I ahve 3 6080's that I intend to mount near the bottom

 

[rvitko]

On a BB you could do it but their will still be debris from bristle worms boring the rocks and I would still prop it up at least a few inches.

 

[skippyreef]

ok that makes sense thanks!

 

[jeffreywilens]

Thanks for the prompt response. Good thing I posted this question. Really, the advertisements for the deco rock should emphasize they are not to be placed on the sand bed.

The advertisements for the magnet holder refer to up to 3/4" glass. This also applies to acrylic? If so, I will first look into the rock structure approach and fall back to the magnet if no other choice.

Also, your reference to the "flow from these pumps" is two foot around confuses me. Do you mean the suction area is for two feet around the intakes? How can that be if the pump is inside the deco rock. I would think the flow would mostly have to come from the back opening of the deco rock if it is sitting on something.

Or do you mean the flow out of the outlet is for two feet (I hope its a lot farther than that). Thanks again for the assistance, its a lifesaver (or pumpsaver at least).

 

[rvitko]

Flow is a 7ft by 2ft column of water on a 6100, it can actively suck in sand like a vacuum cleaner from about 4" through the intakes, I have seen it myself.

 

[jeffreywilens]

Okay, thanks Roger. This is a great resource. I'm going to try stacking the deco rock well off the sandbed like you recommend.

 

[glenns]

Roger,

I have a 6060, and it is a few inches below the top of my 75G tank with a 5" DSB . It kicked up sand on the other side of the tank for a few days so some sand was suspended in the water column until it settled in a new location. Will this cause a problem with the streams? What about sand storms caused by powerheads that get loose?

Thanks.

 

[rvitko]

If you have a sand storm it is prudent to tear down your pumps (all brands) and clean them out. It is no different from how a sandblaster or rock tumbler works, the abrasive material inside slowly sands away the innards of the pump, I have seen extreme cases where it sanded all the way through the impeller well to the resin coating the motor coil inside.