So I built a CSD last night...

[chicagoman_35]

Well, after touring the GA Aquarium on the 25th I decided I needed to improve my water movement... I am trying a Carlson Surge Device.

I have it built and running... It is in a 5 gal bucket sitting on top of my canopy (about 22" above water line). It is fed with a Little Giant 3MDQ, has 1.5" discharge pipe, and a 1" safety overflow...

It cycles every 20 or so seconds, dumping a little over 1/2 bucket at a time. It does induce quite a lot of bubbles into the tank.

Anyone ever mess with a setup like this? Any possibility of reducing the bubbles in the tank?

[theplatypus]

I would think that it would have to discharge below the tank waterline to avoid bubbles.

[chicagoman_35]

It does... The discharge pipe is always below the water line...

Here is a link to the site I built mine after...
http://www.breedersregistry.org/Repr...mple_surge.htm

[JT]

Unfortunately, microbubbles are unavoidable with CSD's because of the amount of air that comes down with the water. No air, and the siphon wouldn't be able to start.

A few years back, Eric Borneman had a surge bucket design that utilized a toilet bowl flapper and a float. The float would rise with the water level in the bucket and pull open the flapper allowing all the water to quickly exit with less bubbles than a traditional CSD. Do a search for one of these.

- JT

[GeorgeW]

I am planning one of these for my 75 when it becomes a reef. I have looked into the various designs and all of them involve some bubbles, but the siphon designs always involved more air. I am currently doing soak tests on the all-pvc toilet setups. There is one toilet mechanism at Home Depot that uses a setup that's quite a good design for the process using minimal space. I'm soaking it right now to test. I've found that at least one "all pvc" should have said "except for the little metal bits", so test anything you're planning to use in a bucket.

One modification of the siphon model I have seen uses a venturi to allow the air to rush out, but minimizes (due to the quick surge) the amount of venturi action by turning upwards slightly inside the discharge pipe, just above the water line.

One of my pet theories (pun intended) is that you could make a hole in near the bottom of your discharge pipe and cover it with a piece of Goretex. That would allow air out, keep the water in, but for a sufficiently large hole, not cause any venturi action. Maybe. I have no idea where to find Goretex without buying a $200 coat so I could test this idea.

There's also an RCSD which uses a pipe to surge out, instead of in. Biggest drawback to those is that most of the designs are in-tank (lost space and/or unsightly) and they require a fairly hefty air pump that might be pretty loud.

[Maxx]

chicagoman_35,
I realize this is an older thread, but is your CSD still working? I'm looking at using two of these on my 58 gallon tank as a test bed for two possibly three on a 120 gallon in wall tank I have planned for the future.

I've done a fair amount of reading on thses and did some paint images of them from "The Reef Aquarium Vol 3".

I will post them up momentarily.

Have you fine tuned your CSD so that it works with less bubbles? According to what I've read, there are ways to reduce the number of bubbles...but I'm not sure how much it will reduce them by.

One method mentioned was to add a siphon break line, (which I noticed was not shown in the drawing Dana Riddle provided on the Breeders Registry link you gave above), and mount it inside the container. I also read that cutting 45 degree ends on the siphon pipe (inside the container) making it look more like an arrowhead, will cause a faster siphon break allowing less air into the surge.

I'm very interested in testing some CSD's for my tanks for a couple of reasons.....

The are inexpensive to make, use very little electricity, and since they can be filled by a powerhead or other similarly small pump, they wont add nearly as much heat to the aquarium, meaning my chiller runs less often...using less electricity...etc.

Nick

[Maxx]

Here is the first image. I'm calling this one CSD ver 2.0 as it shows some improvements Dr Carlson utilized to lessen the bubbles making into the tank.

You can see the siphon break line and the 45 degree angles cut into the siphon pipe itself.




Nick

[Maxx]

Herre is CSD 3.0

No word as to whether or not this cleaner looking version actually reduces the number of bubbles making it to the tank.



The book shows the 6 inch free standing pipe, the 3 inch diameter siphon pipe, and the slots in the bottom of the free standing pipe cut 3.5 inches wide and 2.25 inches high...but I would assume that reducing the pipe diameter, but maintaining the same ratios between the pipes would still allow this to work.

Any thoughts or ideas?



Nick

[chicagoman_35]

I don't use mine any more... I had to break down my tank to replace the carpet. When I set back up I installed a closed loop with a SCWD.