How can I set up automatic water change on my apex using pmups?

Daniel@R2R · Jun 20, 2017

So the question is in the title. I have a classic apex and just got my ATK, so now I'm wondering if I pick up a couple of pmups, could a set something up to either do automatic water changes or at least do them on the click of a button. How would you do it? #apexusers

Btw, I know it can be done with a DOS unit, but I'd rather avoid spending that much cash if possible.

hybridazn · Jun 20, 2017

With 2 optical sensors and 2 pmup this would be easy. Have one pmup turn on at a certain time and have it run until it gets to a sensor and shuts off. At that point have the pmup in the fresh saltwater container turn on and run until it fills to the 2nd optical and then have it turn off.

Bam! Instant water change haha

Daniel@R2R · Jun 20, 2017

hybridazn said:
With 2 optical sensors and 2 pmup this would be easy. Have one pmup turn on at a certain time and have it run until it gets to a sensor and shuts off. At that point have the pmup in the fresh saltwater container turn on and run until it fills to the 2nd optical and then have it turn off.

Bam! Instant water change haha

Would I need to plug the extra sensor into the FMM, or could it just plug into the brain? I'm wondering if I'll need another module to make this happen.

hybridazn · Jun 20, 2017

mdbannister said:
Would I need to plug the extra sensor into the FMM, or could it just plug into the brain? I'm wondering if I'll need another module to make this happen.

I would think another fmm is needed for this

Daniel@R2R · Jun 20, 2017

hybridazn said:
I would think another fmm is needed for this

Not the end of the world, but I was hoping to avoid buying another module. ;Meh

Daniel@R2R · Jun 20, 2017

Oh well... at least adding another fmm would allow me to do some flow monitoring.

littlebangkok82 · Jun 20, 2017

A $250 dos would be the easiest

Daniel@R2R · Jun 20, 2017

littlebangkok82 said:
A $250 dos would be the easiest

It would definitely have the smaller footprint, but too pricey IMO for the function I'm looking for. Not saying it's not worth it to some, but it isn't worth it to me

(I have a 50g cube, so water changes aren't super inconvenient). Buying 2 pmups and a fmm would still be less expensive...and that's still pricier than I was hoping for.

Daniel@R2R · Jun 20, 2017

Plus the fmm would have the added advantage of allowing additional flow monitoring.

brett_schn · Jun 20, 2017

Who doesn’t like carrying buckets? Come on people. Lol. It seems it may be cheaper to just go with a second hand Dos and use that. Not sure though

Daniel@R2R · Jun 20, 2017

I wonder if I could make it work without needing the extra optical sensor (and therefore the fmm). If I set the first pmup to pump out based on a time (could be determined by gph) rather than the sensor and then the other could pump back in until it hits the ATO sensor.

MaddyP · Jun 20, 2017

mdbannister said:
I wonder if I could make it work without needing the extra optical sensor (and therefore the fmm). If I set the first pmup to pump out based on a time (could be determined by gph) rather than the sensor and then the other could pump back in until it hits the ATO sensor.

I don't see any reason you couldn't do this. If the "normal" water level is the top sensor, remove water to the bottom sensor and then replace with fresh water back to the top sensor. So long as you didn't have any siphons in your pmup lines, this would be perfect. You would have to do this several times a day to equal any decent water change, but the programming would be simple. Great idea as a second ATK use!!!

BlueCursor · Jun 22, 2017

DOS is probably the least/best approach. 2 pumps, 2 optical sensors, headaches with salinity swings due to sensors reacting at different intervals . . . just not worth it.

wmo168 · Jun 22, 2017

I was thinking to do the same thing for my 20 gallon Elos Mini, getting more switch, FMM, pump and stuff but I end up will go the DOS route. Otherwise checkout this water change video.. This is the cheapest and easiest...
Thoughts about the video? Hardest is the overflow to make sure it don't drain the entire tank? I will still go to the DOS route, 2 bucket with 2 flow switch connect in each bucket, 1 upper (old water) and 1 lower (New water) to my breakout box as I can schedule it certain day of the week and have it shut off if the bucket is empty or the drain bucket is full... The idea of DOS is to do water change thoughout a time gradually, not drain the entire x gallon and refill it...