Yes, the flow is very gentle out the bottom end.

You could put a huge power head on a smaller tube etc....but generally this is not an issue.

This smaller unit is good for about 40-50Gal with a Rio 180.
A 6" x 2.5" tube will do a 80-90 gal, use 2 smaller ones also, they are easier to hide in larger tanks and do a better job than one single big one.

They alos use much less electric, the larger 20w vs 2 x 5w works out better there also.

Regards,
Tom Barr

Thanks Greg!!!

Great design. I was having problems with my old reactor, which is about 6 inches long, building up about 4 inches of O2 at the top by the end of the day. This was making the reactor pretty useless. Converted it to the new design and now works a lot better, but what a noise the venturi makes with the bubbles going through the pump. Does work very well though. I have taken the tube out of the pump for the time being and just using the blurp hole. Going to monitor but so far still seems to be working pretty well.

James

Tom,
I was curious if you could stick a quickfilter or equivalent on the powerhead
for filtration. Or would this slow the flow enough to compromise the efficacy
of the BVD (Barr Venturi Design)?

Bill

Bill-

Sure, I see no reason why not.
I don't use CO2 at night personally, I really don't suggest others to do that either. Amano is in the same camp on this.

We both have our reasons.

Mine is mainly so I can dose high levekls only when it's needed. This allows me to add higher levels than anyone using a 24/7 method of dosing with much less risk and fish issues.

Since most of the 12-14 hour dark peroid has no CO2 additions, the O2 is still there(and quite high most of the time) the CO2 levels drop off and are a non issue most of the 24 hour cycle.

I can handle being hot for 6 hours a day but I'd hate being hot 24/7.

The higher CO2 also reduces O2 use by other organisms. So adding it only when you need it, allowijng the O2 to stay at a high level till it's all used up seems the best method.

Amano never said much about why, but that's the way he is.

Regards,
Tom Barr

Thanks, Tom, having the ability to serve a dual purpose further enhances the design.

Regards,

Bill

Tom,

I have been running co2 24/7 because my ph will shoot up a fair amount if I don't. I have very soft water where I am and after a 50% waterchange I add about 8gr of baking soda to get a kh of 4(55g tank). Can I buffer my ph some more (baking soda best?) so it wont fluctuate so much? I would much rather have c02 on a timer to cut it out at lights out. I would appreciate any suggestions you might have.

pH and soft water does not matter.
Fish don't mind.

They do mind if you add lots of baking soda etc into the water suddenly.
If you have a KH of 4, there's not need to mess with 24/7, I'm trying to think of why you would need to mess with 24/7 and I cannot think of any other than you want to add CO2 into your filter, that's fine, use a solenoid for on/off in that case.

Regards,
Tom Barr

perhaps i posted this in the wrong section cause it's not regarding the venturi design.

anyhow, my comment was more along the lines of how you mentioned you stop adding co2 at night which is what i want to do as well. i have a controller hooked up to my reg./solinoid which is no problem. the reason i've been running it 24/7 was to keep a stable ph. problem is when i turn off co2 at night, by morning my ph goes from 6.4 (end of day) to about 7.2 (first thing in morning). seems like a very drastic swing to me and i wanted to know how i can avoid this swing...

hope this is a little more clear and thanks for your patience

If you're trying to avoid the ph swing because of your fish, that much
gradual change won't bother them in the least.

Bill Ruyle

FYI, pH dinual changes occur from 6-8 very commonly in natural lakes, 6-10 in some pools with heavy plant biomass.

This occurs daily.

There are plenty of fish.

pH does not matter.

Look at those poor unhealthy fish ADA's tanks have, every one of them turns the CO2 off at night, virtually every contest winner in the top few spoits in the ADA contest does this also.

I'd rethink your approach and rational behind stable pH with CO2 being better for fish.

Apisto's, Altums, Dsicus etc all do great, bred etc.

Guess they are not doing too bad?

Regards,
Tom Barr
Tom Barr