Why is my Sicce return pump slowing down?

Joe31415 · Oct 10, 2024

Just a few weeks ago I picked up a Sicce Syncra SDC 3. I got everything configured, had my water level/overflow/return all balanced and it ran perfectly for the first week or so. However, since then, I've found myself power cycling it about once a week as the water level starts dropping.
I have the speed set to No Mode/Constant, so it shouldn't have anything to do with that. My overflow weir is clear, so it's not that. When I installed the pump, I pulled the plumbing from the tank to the return nozzle and cleaned it all, so there's nothing in there causing a problem.

I have, cautiously*, upped the speed, and while that will fix the problem, it still comes back a few days later.

I'm going to email Sicce, but I wanted to see if I was missing something first.
Beyond power cycling it and playing with the speed, I haven't done any troubleshooting yet. This problem was present out of the box, so I haven't bothered pulling it apart or doing a factory reset. Also, I'm not seeing any troubleshooting information for it in the manual or on Sicce's website.

*"Cautiosly", since I know it runs properly at the speed I have it at, I worry that I might overwhelm the overflow if it suddenly starts pumping at this new, faster, speed.

MnFish1 · Oct 11, 2024

I would consider that your overflow is either blocked in some way - or the pump is too much for your overflow. It's impossible to say without seeing your setup. you should not have to power cycle anything ever. I do not think it's a Sicce problem - but a problem with your setup.

Joe31415 · Oct 11, 2024

MnFish1 said:
I would consider that your overflow is either blocked in some way

If my overflow was blocked, the water in the tank would be getting higher, not lower.

Joe31415 · Dec 26, 2024

Small update: I contacted Sicce and they sent a replacement. They told me I should just need to replace the pump and leave the controller alone. I did that and it was fine for a few weeks and then started acting up again.
I'm going to replace the controller next, but if that's not the issue, I'm not sure what's next. I've cleaned the entire return line so it shouldn't be that. Plus, even if it was some type of blockage, I wouldn't expect it to work fine for a few days, then start slowing down and then be fine for a few more days after a power cycle before slowing down again.

Also, I should clarify that when I say it's 'slowing down', what I'm seeing is the level in the overflow box dropping. I can't think of what that would be other than the pump slowing down.
The pump is new, and therefore (should be) clean and I cleaned the return line. A blockage in the drain would cause the level in the overflow box to rise, not fall, so I don't think it's that. A blockage in the weirs would cause the level in the tank to rise up a bit, the level in the overflow box should stay the same, I think.
Another thing worth noting is that when this happens, my salinity spikes, which is what I could expect if the sump level was too high and the ATO wasn't kicking on until the extra water evaporated. Any type of drain blockage would cause the tank level/overflow level to rise and the sump level too fall, kicking on the ATO and lowering salinity.

Something I've considered is using the Apex or an external timer to shut the pump off for a few minutes once a day to reset it. But that's a last resort.