Calcium Reactor DC Recirc Pump Best Speed

[iamchadster]

So as the title suggests I am curious if anyone has good data on how to run their recirculation pumps on a Ca Rct. The reactors I've used in the past have always had an AC one-speed recirculation pump. Since so many reactors are now coming with DC pumps with a wide range of speed I am curious as to what benefit running a pump at 100% vs 20% etc. would exist.

I own an Octo CR140 and currently have the Varios DC pump running at about 30% with a Kamoer FX-STP2 pulling water through the reactor at 10mL/min.

Links or answers appreciated.

 

[Vinny Kreyling]

Spitballing here but, higher speeds would mix the gas better & tumble the media more, possibly causing it to crumble more from movement.
In the past we had trouble with flow because everything came from that 1 pump.
More speed could also give more flow.

 

[iamchadster]

The media doesn't really tumble that much as it's pretty heavy and the force coming up through a diffuser plate is spread out pretty evenly. I agree with all of your statements I just wish that if these were going to be manufactured with the option that someone would state what a recommended speed might be.

I've been in the hobby long enough to know that there is always the answer of doing to your preference etc but is there any recommendation based on anything more than opinion?

I agree with you in that more cycles through the media would expose the media to more of the co2. Is that important and would running the pump, say at 30%, extend it's longevity to justify the reduced media exposure?

I just find it interesting that I haven't seen a single recommendation on this. Why are the pumps adjustable? Don't get me wrong I love the option but because we now have an option I would just like to hear what folks think is best or reference a manufacturer recommendation etc.

 

[iamchadster]

So I have some data to report and I think I will write something up based on what I find.

I have a Kamoer dosing pump that allows me to dial in a flow of effluent from the reactor so I can see changes in dKH and pH in the reactor very easily from changes in recirculation pump speed.

As suggested above, a greater recirculation in the reactor would expose media to flow more often etc.

I turned down the flow on the pump to 25% over the weekend and saw a direct drop from 9.6 dKH to 9.3. I have a NS trident measuring parameters so I can get good date 4x/24hr period. Last night I turned the recirc pump back up to 50% and saw a rise to 9.5 this a.m.

What would be more useful i think is a plot of effluent dKH vs % of the recirc pump speed. I will see if I can create some data via the Apex to post to find that sweet spot if it exists.

 

[Vinny Kreyling]

You will have to keep the CO2 constant for a set of plots.
Changing CO2 will require another plotting.
Both have the same effect which is why you should do only one @ a time or never know which one worked.

 

[joseserrano]

Interesting topic. I also wondered what the advantages of a dc pump really is