New Year, New Challenges - CaRx & Versa

[bakbay]

Been busy during the New Year and found out that my Alk has been plummeting while pH was getting past 8.5 and pH inside the chamber dropped. Well, the Versa was pulling water but not at 55mls so definitely not meeting tank demand at 1.5dKH/day! Alk went from 9dKh to 6.5dKH in 2ish days - not good. I’ve replaced the tubing - glad I got a spare! Hope things will slowly climb back up…

These things only last 4-5mos, which sucks! I have a Kamoer in storage — does it last longer? Perhaps I should go back to a CarX valve, which was unreliable as well…

Thoughts? What do you guys use for your CaRx? I do have a Sicce 0.5 feed pump push water to the chamber.

 

[Jamie814]

Perhaps I should go back to a CarX valve

I use this reliable valve, it is expensive though,
https://aquacave.com/precision-needle-valve-with-1-4-john-guest-style-fittings.html

But I also have the effluent go through a single canister 5 micron ro sediment filter before the valve to keep any tiny sediment from clogging it. Works perfect.

 

[Jamie814]

If you really want to control alk stability and pH you can do what I do and use a DOS (or versa) to dose extra effluent a few hours after lights on to a few hours after lights off as uptake is higher during this period. It also helps reduce pH swings a bit more due the additional lower pH effluent being dosed during the lights on period.

Dosing pump tubing really doesn't last long because of the large volume that goes through a CA reactor. By dripping the majority of effluent demand the pump tubing lasts much longer.

 

[bakbay]

If you really want to control alk stability and pH you can do what I do and use a DOS (or versa) to dose extra effluent a few hours after lights on to a few hours after lights off as uptake is higher during this period. It also helps reduce pH swings a bit more due the additional lower pH effluent being dosed during the lights on period.

Dosing pump tubing really doesn't last long because of the large volume that goes through a CA reactor. By dripping the majority of effluent demand the pump tubing lasts much longer.

Interesting. I dose using a GEO CaRx 24/7. It’s been stable for the last 2+ years and happy with it. I’m just sick and tired of replacing the versa tubings every 4’ish months!

I don’t worry about pH since I’m doing recirculating CO2 scrubbing. That said, my pH swing is too wide and was thinking of dosing kalk at night to flatten out the curve.

 

[bakbay]

I use this reliable valve, it is expensive though,
https://aquacave.com/precision-needle-valve-with-1-4-john-guest-style-fittings.html

But I also have the effluent go through a single canister 5 micron ro sediment filter before the valve to keep any tiny sediment from clogging it. Works perfect.

It’s not expensive since each Versa tubing is $19 and I just bought replacements just in case. I’ve used this before but they do go bad (clog) over time — perhaps I didn’t use a filter prior. I might reconsider going back to this and add a filter like you.

I like the Versa (or other peristaltic pumps) since I can digitally control the flow rate vs counting bubbles.

 

[Jamie814]

Dose ecotech specify what type of tubing material they use in their pumps? Some last much longer than others.

 

[Jamie814]

You can get bulk tubing here in just about any type, I've used them before for projects in the past, very good pumps. I would think you can just replace the tubing on the versa instead of the whole head every time.

Raw Pump Tubing by Type Archives - Simply Pumps

All of our pump tubing is designed specifically for use with peristaltic pumps. In many cases it can also be a cost effective option for simple fluid transfer.

simplypumps.com

 

[bakbay]

Dose ecotech specify what type of tubing material they use in their pumps? Some last much longer than others.

They do sell 25’ tubings for $10 so yes. However, I’m kinda fed up with replacing them so after this batch, going to retry my Kamoer.