What's Your Bps?

dj2606

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Apr 23, 2018
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Hey folks,

I'm curious what bubble rate others are using on large systems, 125g and above.

1. What's your BPS?
2. What method are you using for CO2 diffusion?

Thank you!
 

Tim Harrison

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Bubble rate doesn't really mean very much, it depends on diffuser, water chemistry, bubble counter etc etc; it'll be different for every tank.
It's especially difficult to measure in a large tank; very often the bubble rate is so high it's impossible to count.
You're better off with a drop checker, aim for lime green at lights on and all the way till lights off.
To achieve this, for example, my gas comes on 3hrs before the photoperiod starts and goes off 2 hrs before it ends.
 

dj2606

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Apr 23, 2018
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Yes, I know it's different on every tank and multitude of variables at play. However, I was just looking for a ballpark or general idea of what others are using/experiencing with their setups. As for not being to count the bubble rate, taking a short video in slow motion using a phone multiple times and finding the average will give a ballpark estimate (obviously the more you take to average the more accurate the measurement). It may not be necessary to know the BPS when using a PH monitor but I cannot be the only one who was curious about what their rates are....or maybe I am, dunno. I currently use neptune apex to monitor PH. I don't use a drop checker as there is too big of a delay to accurately measure CO2 concentration when I can easily open my cabinet door, look on phone/laptop and get a much more accurate reading from the apex. Again I was curious what others are experiencing.


@Phishless what type and size reactor are you using? Filtration?
 

Greggz

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On larger tanks counting bubbles is pretty useless, as the CO2 is a constant stream. And what is the size of a bubble? Could be much different from tank to tank.

Many with larger tanks use a Dwyer flow meter to measure CO2 usage. Mine is set at 45 cc/min in my 120G going into a Cerges reactor.
 

Phishless

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Corner filter of Poret foam.
300GPH pump feeding a DIY reactor with bio-balls and spraybar across the back.
 

Greggz

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tiger15

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Aug 12, 2017
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Since bubble size varies with the set up, someone's bps may not be comparable to yours.

I no longer use the standard bubble counter of my Milwaukee regulator anymore because it dried up long time ago . Instead, I use my Tunze diffuser (similar to Barr's venturi diffuser) as a substitute bubble counter where the bubbles are larger and slower to count. With that, I am injecting about 2 bps to achieve 1 pH drop in my 75g. If I convert it to the standard bubble counter, I am probably getting 4 to 6 bps which will be too fast to count.

https://www.aquariumplants.com/Tunze-CO2-diffuser-p/tun7074.500.htm

Is it just me, I noticed the bubble size increases with pressure drop in the cylinder, so later bps injects at higher effective rate than early bps. So bps is not a reliable way to gauge the effective injection rate because the bubble size varies with cylinder pressure, and likely also with ambient temperature and pressure.

Since the Tunze diffuser will accumulate an air pocket in the tube, the location of the air pocket boundary is a good indicator of the injection rate. I am adjusting the bps so the the boundary is near the mid point of the tube. and the maximum bps I can inject without wasting is when the boundary reaches the bottom the tube.