Perestaltic pump on 3171

X-37B · Feb 8, 2020

Roger, curious if you know of anyone running a peristaltic pump on a 3171. My 3171 keeps putting out lower amounts. Turn it to 25ml minute and over a couple of days it is 15. Not sure why. Co2 pressure does not change. Sump is kept clean. Any thoughts or possible issues running a peristaltic pump for effuelt stability.
I have a masterflex on hand.

rvitko · Feb 10, 2020

I suspect there is a reason but I don't know why. I am not sure the peristaltic pump is a good solution. My main thought from going through this with someone else is that it is media related, or it could be pump related, or a combination, for example the media is fouling the pump so it slows down or the passages in the lines clog. I might first try the Tunze Calcium Carbonate. I use the 3172 and it has been incredibly solid, I previously used the 3170, the basics of all 3 models are the same, only the volume and pump varies (3172 uses the same pump). I would assume we are losing vacuum or pressure somewhere from clogs or leaks.

X-37B · Feb 10, 2020

I use the tunze media. It stays 25 ml a minute then drops to 20 in a few days and went as low as 15. Turned the screw and it is fine for a few days. I dont believe its clogged as my sump is clean. Check out the pic.

rvitko · Feb 10, 2020

Do you know of any leaks? FWIW, I have another customer with this issue and I have a customer with this issue with another brand of calcium reactor who called just to pick my brain. My general assumption from my own experience is that somewhere we are drawing in air or losing pressure/suction. I would verify everything for CO2 in is secure and no atmospheric air can be drawn in. I would also check that no water leaks out. The guidance I got from Claude Hug who is the inventor of these models is that generally such an issue is either leaks or a clogged intake/pump or too much CO2, to low of a drip rate (which can also be air drawn in at a loose CO2 line). I had a similar issue when I first installed my 3172 and the problem was I tried to use the Tunze tubing on the carbondoser, it fit poorly and air was drawn in, CO2 was only added intermittently, this also seems to be the issue the customer with the other brand reactor had. To solve it I used the Carbondoser tubing which is quite stiff, I used our checkvalve and from the checkvalve to the reactor I used our tubing.

X-37B · Feb 10, 2020

I use tunze check valve and tubing from bubble counter to pump. Co2 is stable and does not change. Not sure how it could be plugged as media and reactor are new and only running now for 6 weeks. I checked for air leaks this weekend and found none. May try increasing effluent rate to 30+ and lowering co2 input. Co2 is 68 bubbles a minute and stable. Co2 2 stage pressure is 1 bar/15 psi.
Alk is stable at 8-8.2 so no worries there.

rvitko · Feb 10, 2020

For reference, I use less CO2 on my 3182, which holds about 3 times the media and water. I run 1 bubble a second and my drip rate I don't set so precisely as you, I basically set it so the amount of drops is just distinguishable from a stream, roughly 6 drops per second. I might reduce the CO2 and the drip rate. For the most part, the end result is what matters, if the drip rate slows down, within reason it just is getting more concentrated.

X-37B · Feb 10, 2020

rvitko said:
For reference, I use less CO2 on my 3182, which holds about 3 times the media and water. I run 1 bubble a second and my drip rate I don't set so precisely as you, I basically set it so the amount of drops is just distinguishable from a stream, roughly 6 drops per second. I might reduce the CO2 and the drip rate. For the most part, the end result is what matters, if the drip rate slows down, within reason it just is getting more concentrated.

Ok I will give it a try. Thanks.

X-37B · Feb 10, 2020

rvitko said:
For reference, I use less CO2 on my 3182, which holds about 3 times the media and water. I run 1 bubble a second and my drip rate I don't set so precisely as you, I basically set it so the amount of drops is just distinguishable from a stream, roughly 6 drops per second. I might reduce the CO2 and the drip rate. For the most part, the end result is what matters, if the drip rate slows down, within reason it just is getting more concentrated.

Checked everthing tonight when I got home.
I missed looking at the inside of the blue screw adjuster. The hose was bunched up to one side. Readjusted the hose so the screw was right on top of the hose. Reset and will check in the morning but I think that was it. It ran at 25ml a minute for 4 weeks straight. Something to look for if anyone else runs into the same issue.
I must have somehow twisted the hose without knowing.
It does adjust pretty easily when the screw is adjusted right. Thanks for the help. Will let you know how it goes in a few days.

X-37B · Mar 3, 2020

Update. I have been talking to a member who has the same issue.
He said Tunze engineer said to run smaller diameter hose. Same as effluent.
So I changed to smaller hose to try.
I set it at 30ml minute and bubble per minute is 60 now. Has not moved in 2 weeks and alk is steady at 8.
Again simple and awesome carx imo.

X-37B · Jun 2, 2020

Update. The flow has slowly decreased over time requiring adjustment.
I however found the issue and want to pass it on.
Clean the intake strainer and small blue sponge!
I feel like an idiot but I overlooked this from the start.
I will now clean it monthly.
If your sump has alot of detrius you may want to monitor it closely.
When the flow goes down it needs to be cleaned.
Since cleaning its right on target.
Simple and very well designed carx.

X-37B · Sep 20, 2020

Roger. I took my 3171 out to clean after 10 months running.
Actually did not need to be cleaned.
I emptied all the media and was removing the strainer and the flange came off.
It appears to be just siliconed on.
Should I use silicone or something else to repair it.
I have had it for over 2 years I believe. Its only been running 10 months.
Let me know. Thanks, Sven.

rvitko · Sep 21, 2020

It is 2 part polyurethane, what you describe is a defect from the first models and we would replace the body. Can you email me your purchase information? Tunze at sbcglobal dot net.