Auto Water Change or Monthly Water Change?

[Oshanickreef]

I would love to get a discussion going on what is more desirable for a reeftank. I have a mixed reef SPS heavy. Been doing AWC for a while now. Corals are okay. Some sps colonies die randomly. I recently have done a few 20% Water changes and noticed my lps fluff up nicely. But i think it affects my sps slightly in a negative way. But also not sure. What are everyone’s thoughts?

 

[Randy Holmes-Farley]

I cannot see any drawback to awc except cost/space of the equipment and a very slight reduction in efficacy (that is easily made up by changing a little more). Folks who turkey baste the rock probably prefer once a month water changes.

OTOH, AWC are far less work, much less chance of stress, no need to heat or even otherwise match new salt water (for example, salinity, alk, etc), as long as you know what effect it will have.

I’m my tank, it only took a few minutes a month to make a batch of new salt water.

 

[skey44]

I think the age of the tank will dictate what is best. My tank is still going through some initial algal blooms and imbalance at month 3 and I like to turkey baste rocks as needed and siphon sand. I have a feeling over time as my tank becomes more established and needs less hands on cleaning AWC may be the way to go.

New tanks- weekly 7-15% change
Established low algae tanks- AWC

I find that getting temp and salinity correct I don’t see any ill effects on my corals doing a one or two bucket water change weekly on my 80 gallon display. Just adding some acros now so FWIW, but their PE remains good after a WC so far.

My goal parameters are basically in line with my salt (TMPro) parameters and relatively stable with AFR dosing (and 3part to correct individual numbers as needed) so water changes shouldn’t be changing my chem much.

I am also a fan of the weekly reset/assessment of the tank a WC brings. It makes me pay close attention to my inhabitants and major parameters so there’s a hands on no autopilot thing that helps me too. If it was all automated I would personally be less in tune with my trends and how corals are looking etc. weekly WC have been a benefit for me especially with a new tank.

 

[Devaji]

I ovten wondering this too.
I really like what @skey44 said that sumed up my thoughts too.
I stil have to do manual WC as I still have some algae I am fighting with my tank about a year old.

but once I get it under control it AWC time.