Why is the Neptune DoS this loud?

[certain_code]

I’m trying to really understand the system here but I’m really struggling to figure out why the Neptune DoS is so loud compared to other dosing pumps. The much cheaper BRS dosers can to 50ml/min and are easily half the output of noice than the DoS at 25ml/min. I also do not see any difference in the accuracy even. Is my DoS having issues or is this just how Neptune really decided to accept this pump? What is the common thoughts on this given it’s time in the market at this point?

 

[ZombieEngineer]

It's the stepper motor they used. The more quiet options you mentioned use brushless DC motors, which are quieter but are not nearly as precise and have shorter lifespans. Stepper motors are a lot louder, but are incredibly precise and last about 4 times longer.

 

[pfoxgrover]

I have a bunch of them and had to move them to the garage and run ro line and a USB cord through the attic.

 

[certain_code]

It's the stepper motor they used. The more quiet options you mentioned use brushless DC motors, which are quieter but are not nearly as precise and have shorter lifespans. Stepper motors are a lot louder, but are incredibly precise and last about 4 times longer.

But what does 4x really mean? At what point does the accuracy really matter that much? I’ve been running both for 3 months and see no difference in accuracy at the same rates between cheaper options.

 

[vtecintegra]

Poorly engineered in my opinion. Lots of complaints on the noise. I wouldn't be surprised if a better version is being developed.

 

[Clownfishy]

Poorly engineered in my opinion. Lots of complaints on the noise. I wouldn't be surprised if a better version is being developed.

I hope so. I cannot fault the accuracy, it is outstanding but it is so noisy, it restricts what I can dose at night as it is so loud.

 

[ZombieEngineer]

But what does 4x really mean? At what point does the accuracy really matter that much? I’ve been running both for 3 months and see no difference in accuracy at the same rates between cheaper options.

A stepper motor's lifespan is based on number of rotations and the quality that neptune got is good for 5,000 hours at maximum speed. The slower you run them, the longer they last ex the Neptune one runs at 250ml/min so it can run for 5,000 hours or 18750 gal at full speed. It can run for 178,571 hours at 7ml/per or also 18750 gal

A DC motor that is of the same quality that is also rated for 5,000 hours can only run 5,000 hours with minimal start/stop operations. Every time you start it, you reduce the lifespan. At 50ml/min this pump would last for 3750 gallons, but more realistically will only get around 2000 gallons due to the start/stop operations damaging bearings from the high startup torque. This is why there is a common complaint that the BRS 50ml ones only last like a year maybe 2 if you're lucky for a moderate sized 120 gallon tank. The BRS 1.1ml ones get their life reduced from the start/stop operations, but they do undervolt those so the lifespan is increased. You can probably get about 80 gallons out of one of those, which for me is 5000 days of dosing, so that is worthwhile lifespan.

 

[ZombieEngineer]

Poorly engineered in my opinion. Lots of complaints on the noise. I wouldn't be surprised if a better version is being developed.

Agreed. I wish they got a different stepper motor with more microsteps sp they could take the audible noise to >20kHz so it would only bother dogs and not humans.

 

[BanjoBandito]

As someone that ran a coralbox wifi pump before my DOS, I think the noise level is “fine”. It’s under my cabinet and I can hear it but it’s not a good awful CHUNKA CHUNKA of that coralbox. I wanted the accuracy for carbon dosing…. Maintenance doses would be like .4 ml per day on a tank my size (106 gallons total volume). I don’t trust a cheap pump to do that.