Marineland Flexible Bubble Wand

[isLu]

I recently purchased a 48" bubble wand for my tank. It goes in a straight line across the back of my tank. My questions is, I have a sand substrate (Onyx) and I can't figure out the best way to implement the bubbles. Currently, I have it buried under about 1/2" of the sand, but the more it fills up with air, the more the bubbles are blowing the sand off and exposing it. I would bury it deeper but I'm afraid it will just trap all the bubbles, or create a few large ones instead of many small ones.

Has anyone else had any luck with bubble wands under sand? Or is there some other creative way to hide it?

 

[Schmill]

I don't have sand, but also didn't like the effect that burying my wand under my gravel a bit had on the bubbles.
I've used suction cups and heater clips to fix my wand to the back of the tank just above the substrate, and then have bogwood / ornaments / plants around it too.

 

[isLu]

I don't have sand, but also didn't like the effect that burying my wand under my gravel a bit had on the bubbles.
I've used suction cups and heater clips to fix my wand to the back of the tank just above the substrate, and then have bogwood / ornaments / plants around it too.

I see. I had mine buried about half an inch under, and noticed several problems. The most noticeable being that there were large 5-6 inch gaps with no bubbles at all, as well as portions of large bubbles instead of the many smaller ones that I was hoping for. I guess I will see if I can find a 48" wooden dowel or something and cover it in java moss. I don't have enough plants/decorations to cover the wand by itself.

Any idea why parts of the wand aren't releasing bubbles?

 

[Schmill]

Is the wand actually not releasing the bubbles, or is it because you have the substrate on top of it? The substrate will channel the air together.

If it's doing the same thing in free-water, it's possible that your airpump isn't putting enough pressure into the wand., try disconnecting the wand from the pump and blowing really hard down the pipe yourself, if you can make the whole wand bubble you need a bigger pump

 

[isLu]

Is the wand actually not releasing the bubbles, or is it because you have the substrate on top of it? The substrate will channel the air together.

If it's doing the same thing in free-water, it's possible that your airpump isn't putting enough pressure into the wand., try disconnecting the wand from the pump and blowing really hard down the pipe yourself, if you can make the whole wand bubble you need a bigger pump

It releases bubbles, but they're very inconsistent and there are two gaps. The wand looks like this, where - is a gap, . is small bubble, o is large.

.......------...............oooo...............oooo...........------------.......oo Start

Some of the large bubbles are due to sand, but I still can't figure out the gaps. And to make things more confusing, I have an air pump with two outlets on it. When the second outlet is plugged, the air bubbles drop in half. Shouldn't there be twice as many bubbles with the second outlet blocked, since that directs 100% of the flow to the first outlet? I don't understand why adding more air pressure to the wand causes less bubbles.

It could also be the check valve I have on there cutting airflow, but I'm afraid of not using one because I've had an airline back flow before when the power went out. I'll see what I can do with that, though.

Also, is there a certain pump you would recommend? I have no idea what I currently have, as they are second hand and fairly old, but I've noticed on newer pumps, only the top of the line ones have dual outlets on them, so I can't imagine the ones I have not being strong enough. Especially since air comes out fine all the way on the other end.

Thanks for the help!

 

[Schmill]

Did you try blowing dwon the airline into it as I suggested (like trying to blow up a balloon)? This will tell you straight away whether the wand is blocked, or if you just need more air pressure, (which are the 2 most likely possibilities).

As for the air pump;

I can see your reasoning on that if you block one outlet all the air should come out the other, but they don't work like that. That would be correct if there really was just one pump and 2 outlets.
What you actually have is 2 bellows (like the old things for blowing fires), each with one outlet, all within one box.
As an overview you have an arm inside the 'box'.
When the arm moves left, it pushes air out of Bellow #1 through Outlet #1, and sucks air (from outside) into Bellow #2.
When the arm moves right, it pushes that air out of Bellow #2 through Outlet #2, and sucks air (from outside) into Bellow #1.
This is repeated many times a second, (around 50 times if my brain is thinking straight) and this is what makes you seem to get constant air flow.

So when you block outlet #2, the arm moves left blowing air out of outlet #1, and sucking air into bellow #2. The air then tries to move right again, but bellow #2 is full of air and you have blocked the outlet, so it can't push the air out & therefore can't move very far. Because the arm can't move very far it means it doesn't suck much air into bellow #1, and then when it moves left again there isn't much to blow out.

Hopefully from that you can see how blocking on outlet actually reduces the airflow from the other one as well.

What you want really is one of these (available online or from your LFS)

You can then use some airline from each outlet to connect to each side of the T, and then run your airline (and checkvalve), from the center piece of the T to the tank.

Totally agree about your checkvalve, don't remove it, it's always better to have one, (in fact I use 2 because I am overly-cautious!), but if you do the above T-ing the outlets together, remember the checkvalve must be fitted to the pipe between the T and the tank, not between the T and one of the outlets, otherwise the other outlet will still allow back-syphoning

Let me know how you get on