Co2 check valve

**hann** · 27th Oct 2014, 10:58

need some help here. I have been using the ocean free (OF) solenoid with the silver bubble counter that comes with it for 8 months. Yesterday I just got the co2 cylinder refilled.

When the solenoid is switched off, the bubbles slowed till it stopped to a standstill (this is normal I know). However, This is when I am concerned with: the last bubble in the bubble counter coming out from the silver check valve stays there for like 2 seconds before it slowly goes back into the valve. Is it considered as backflow? I check the water in the bubble counter and it did not deplete though. Also, there is no water trace at the base when I take out the bubble counter to check.

Also, is it normal to take a while for the bubbles to appear after the solenoid is switched on and when the bubbles comes, it is like gushing out before it returns to normal 3bps?

Any issue with my co2 setup?

**Urban Aquaria** · 27th Oct 2014, 15:34

That sounds normal, my bubble counter does that too, the last bubble sometimes just sits at the counter nozzle and then slowly disappears. Its just from the change in pressure as the Co2 gets used up in the tubing and diffuser.

Do you have an additional check-valve installed between the bubble counter and diffuser? That will help prevent tank water from flowing back and mixing with the bubble counter water.

Its also normal for the BPS to be a bit faster when the solenoid is switched on initially every day, thats because the tubing and diffuser doesn't have any Co2 pressure at the start, so the initial gas injected has an easier time to fill them up. Once the pressure builds up within the tubing and diffuser, then the BPS will settle to a more consistent rate.

**hann** · 27th Oct 2014, 16:49

Hi UA, thanks for the reply. My bubble counter is similar to those brass counter and there is no tubing between the bubble counter and the solenoid. The base of the bubble counter is a check valve. I have a plastic check valve at the output of the bubble counter to prevent water to back flow to the bubble counter.

**Urban Aquaria** · 27th Oct 2014, 16:53

Originally Posted by hann

Hi UA, thanks for the reply. My bubble counter is similar to those brass counter and there is no tubing between the bubble counter and the solenoid. The base of the bubble counter is a check valve. I have a plastic check valve at the output of the bubble counter to prevent water to back flow to the bubble counter.

Yeah, that's the common connection layout for most Co2 injection systems, i use that layout too.

**hann** · 27th Oct 2014, 22:33

When I was back from work today, I noticed my co2 flow dropped from 3 to 1bps. This never happened before and it had always been very stable. The only thing was I had my cylinder refilled on Saturday at NA.

I did not know what went wrong but to play safe, I removed the silver bubble counter and replaced it with a Taiwanese plastic with a check valve. Interestingly, this bubble counter also showed 1bps. Without turning the small knob at the solenoid. What I did after that was turn the knob up to 3bps. Till this posting, the flow is stable at 3bps

I suspected that the silver valve in the silver bubble counter was spoilt. I shook it hard and some water in the bubble counter came out at the base of the valve. Can I conclude that the valve was leaking with this experiment? Or is it normal and not robust enough to take a hard shake?

Last question that runs across my head: can a fully filled cylinder distort the bubble counting? Like setting a 3bps on the first day was a false indication and now it was returning to the original knob setting. Still very puzzled and will monitor these 2 days whether the bps will drop again.

**Urban Aquaria** · 27th Oct 2014, 23:14

If some water drip out of the base of the bubble counter, then it probably means the in-built check-valve isn't working properly anymore (water should not get pass its check-valve)... maybe it could just be worn out or somehow corroded.

Btw, do you use distilled water or aquarium water to fill the bubble counter?

**hann** · 28th Oct 2014, 00:07

I use tap water to fill the bubble counter

**Urban Aquaria** · 28th Oct 2014, 09:19

Hmmm... i use distilled water for my bubble counters (i just keep a small bottle of distilled water from supermarket for doing such refills), not sure if it actually helps though, the bubble counters i use have been running for 2+ years so far without issues.

I guess it could be possible that other types of water like tap water or aquarium water may contain minerals/chemicals that may corrode or clog the bubble counter's inbuilt check-valve over time, so perhaps distilled water may help prolong the valve lifespan.

**atolylica** · 28th Oct 2014, 09:31

Sorry to intercept, but I have a question similar to the subject you guys are talking about.

Since I'm using the ISTA external reactor, I cannot disconnect the top cover of the 'check valve cum bubble counter' because air will escape and aquarium water will automatically backflow and fill up my bubble counter. I've been doing this for quite some time now and so far there is no issues.
UA, I saw you're also using the same reactor as me. How do you topup distilled water as you mentioned?

**hann** · 28th Oct 2014, 09:37

Hi bro atolylica, I assume you do not have another check valve between the reactor and the bubble counter. This should stop the aquarium water to backflow to the bubble counter.

**Urban Aquaria** · 28th Oct 2014, 09:38

Originally Posted by atolylica

Sorry to intercept, but I have a question similar to the subject you guys are talking about.

Since I'm using the ISTA external reactor, I cannot disconnect the top cover of the 'check valve cum bubble counter' because air will escape and aquarium water will automatically backflow and fill up my bubble counter. I've been doing this for quite some time now and so far there is no issues.
UA, I saw you're also using the same reactor as me. How do you topup distilled water as you mentioned?

You need to install an additional check-valve in the Co2 tubing between the bubble counter and reactor, that will prevent tank water from back flowing into the bubble counter (and avoid tank water mixing with the bubble counter water too).

**hann** · 28th Oct 2014, 09:41

Bro UA, I am just concerned that my co2 setup has more internal issue which I do not know. I am still trying to find out the root cause to the reduction of bps. After changing to the plastic bubble counter, it was still 1bps till I turn the knob to increase it to 3bps. Prior to this, the silver bubble counter cum check valve was running at 3bps from Saturday after I refilled my co2 cylinder till this issue occurred.

**Urban Aquaria** · 28th Oct 2014, 10:28

Originally Posted by hann

Bro UA, I am just concerned that my co2 setup has more internal issue which I do not know. I am still trying to find out the root cause to the reduction of bps. After changing to the plastic bubble counter, it was still 1bps till I turn the knob to increase it to 3bps. Prior to this, the silver bubble counter cum check valve was running at 3bps from Saturday after I refilled my co2 cylinder till this issue occurred.

Yeah, it could be due to the restored full pressure in the re-filled Co2 tank which change the behavior of the output gas flow rate (like what you mentioned), i guess as long as the current adjusted BPS is relatively constant it should be working properly.

But just for confirmation, maybe try doing a leak test using soapy water to check and see if any of the connections have slow leaks (might have occurred during re-connection of the parts), at least that will eliminate those possibilities.

**vinz** · 29th Oct 2014, 11:05

Hann,

I have the same OF CO2 regulator with solenoid and bubble counter. Brand new, so haven't refilled cylinder yet. Just want to mention that when I bought it from NA Nature, Chan cautioned me several things:
1. Make sure to fit back the small O-ring below the bubble counter. It is suppose to be fitted on the nipple of the regulator before you screw on the bubble counter. If you need a photo, let me know. I should be opening up the darn thing to re-fill water...
2. Not to over-tighten any part of the bubble counter as the transparent plastic may crack.

So, in case you didn't notice or realise, do check whether your O-ring is still in place and that it is still in good condition.

**hann** · 29th Oct 2014, 11:13

Thanks bro vinz. I have given up on the bubble counter that comes with it after seeing water seeping out of the base when I did a hard shake. Now using the plastic cheap and good Taiwanese bubble counter. So far so good and also because there is a tubing between the check valve and solenoid, I feel safer than a direct connection. Just in case the silver check valve in the original OF counter bubble fails.