Auto water change REALLY?

[code4]

I did think of that as I have small mandarin so I plan them during daytime when most fish active and mandarin are hiding in the rocks and won’t get sucked up threw power head accidentally.

I also have a pair of mandarins. I wish you well as I like the idea. Just too uncomfortable to try it. And I know the ocean really throws fish around at times also. I do blow off my rocks. Just in a more controlled, mostly risk free way. I have also lately decided to use the incoming water to stir up the sand-bed a bit where it is hard for me to vacuum. I think if my tank were not so deep it might be a bit easier to keep "stuff" from settling into the sand-bed. I also probably feed them more than necessary.

Shelley

 

[Heabel7]

http://reefkeeping.com/issues/2005-10/rhf/

I remember reading this in the past. Thanks for posting it.

 

[PooseReefer]

For me, the purpose of the water change is detritus removal. I otherwise notice no difference before and after the water change. I keep my other tank parameters stable, and could probably get away without doing water changes. But having been down that road 10 years ago with disastrous results, I have decided to make water changes part of my routine. So I agree with the OP in that I would see an AWC as more un-necessary than useful, without the detritus removal. One of the reasons I have a 150 gallon sump is so that no matter my water flow, the sump is never turbulent enough that detritus can't settle. I see it as my dropout box, and part of it's purpose is to allow a place for detritus to settle, making it easy to siphon out. When the bottom of my sump gets covered it light brown sludge, that's my visual clue that it's time for a water change.

Like many I have been considering the idea of a continual water change system but cannot get the image of what I take out with each water change out of my head. I pull directly from the sump and get some very heavy sediment water out that way, making sure to suck the detritus off the bottom and between live rock. The first 5 gallons is basically opaque and I do this every two weeks. I just put on a filter roller so maybe if that changes significantly I may go auto, but I'm taking out 15% of the WORST water every two weeks, not just 15% of random filtered water. The points people making that continual is x-percent over a month vs two or one large changes seems irrelevant as the traditional water change has the advantage of "choosing" what you are replacing. There is just no way the continual is removing as much of the material that is breaking down into nitrates.

 

[RMS18]

The idea is great for bare bottom tanks not so much with a sand bed. Sand bed should be cleaned weekly to avoid issues down the line. Those horror stories of sand beds crashing tanks years down the road are due to poor maintenance. You can stir my sand bed at anytime and it will not release any brown nasty stuff. With a bare bottom and good water flow build up on the rocks will be minimal so a auto w/c makes sense and can work.

 

[lefkonj]

The idea is great for bare bottom tanks not so much with a sand bed. Sand bed should be cleaned weekly to avoid issues down the line. Those horror stories of sand beds crashing tanks years down the road are due to poor maintenance. You can stir my sand bed at anytime and it will not release any brown nasty stuff. With a bare bottom and good water flow build up on the rocks will be minimal so a auto w/c makes sense and can work.

An AWC is not about never cleaning the sand bed it is about not having to manually do a water change. I would say that my tank with AWC is much more stable when it comes to the chemistry then when I did it weekly or bi-weekly. Some people have stated that your sump should be as clean as you display tank, while others state that 'there is good in that dirt/sponges/etc/etc in the sump so why clean it.... I think if it works for you awesome.

 

[Dr. Jim]

I hesitate to post this because I know many will say it is a mute point...but I'd like to present a completely different perspective when considering the AWC topic:

Which is less stressful to "sensitive" corals (like SPS):
Stressing them just a little every day (i.e. AWC), or
Subjecting them to just one, "larger" stress once a month?

I started AWC about a year ago when I got my GHL Controller. (It seemed to make logical sense to take advantage of AWC since I now had a controller). For the previous 50+ years I changed water with buckets (biweekly, monthly, every few months.....it varied).

But, while I was struggling to keep my SPS frags alive this past year (due to a host of factors) I started wondering "which method would stress corals the least". In my case, anything I could do to relieve stress needed to be considered. If I wasn't having problems with my SPS frags, maybe I wouldn't have even considered the comparison.

I'll be the first to admit that it probably doesn't matter a whole lot in most cases but I would guess that if corals could talk, they would say that they prefer one method over the other. I wonder which one? My guess is that daily changes are probably more stressful than monthly (or less frequent) changes.

 

[RMS18]

An AWC is not about never cleaning the sand bed it is about not having to manually do a water change. I would say that my tank with AWC is much more stable when it comes to the chemistry then when I did it weekly or bi-weekly. Some people have stated that your sump should be as clean as you display tank, while others state that 'there is good in that dirt/sponges/etc/etc in the sump so why clean it.... I think if it works for you awesome.

What do you find to be more stable about your tank now? Something measurable ?

 

[((FORDTECH))]

I just started doing daily auto water changes with dos 3 days ago. Mainly decided this because I’m lazy and blow off weekly or biweekly changes so now no excuses. I am following this thread and will reply back with my findings

 

[lefkonj]

What do you find to be more stable about your tank now? Something measurable ?

Just about everything. Mag, Nitrate, Phos.... all flat. Don't change at all. You could test daily weekly monthly they don't really change at all. All is the only one that has but that is in uptick of consumption, so you have to increase dosing.

 

[RMS18]

Just about everything. Mag, Nitrate, Phos.... all flat. Don't change at all. You could test daily weekly monthly they don't really change at all. All is the only one that has but that is in uptick of consumption, so you have to increase dosing.

With consistent feedings and the same export methods po4 shouldn't change along with nitrate. Alk and cal being dosed daily will maintain if dosing is set up correctly. My point here is I do not think you gain stability with a/w unless one is not able to maintain their system on a routine. I will only have fluctuating po4 if I was to feed double the food, dump in tons of reef roofs or do anything outside my daily routine for feeding which is the same each day. Plus w/s are a poor way to reduce po4. Po4 is the same before and after a weekly water change at 15%. No3 will land at a number and stay there according to fish bio-load and feedings along with export. If alk, cal and mag are being replenished by daily w/c then I'd say your system is not demanding on those due to slow growth, or not much coral / coraline. Not saying a/w are a waste but they do not create stability if you have the proper export and import routines set up. I use water changes to export debris / detritus in the sand. All elements are dosed, and nutrient export is handed by cheato / gfo / live rock.

 

[Lionfish hunter]

Had the same thing happen when cleaning out my mixing barrel. Grey residue plugged up the hose barb on the new water side of the DOS. Apex salinity probe may not be awesome but it is directionally good enough to catch something like that. In my case the DOS head made a funny noise so I noticed it right away.

I am setting up an auto water change system with apex and do not want to pay for a salinity probe. Thinking about programming my auto top off to turn off the same time every day and program the auto water change to happen during this time. I will change a sizable amount of water, maybe 5 gallons every day all at once. I have the liquid level sensor, so I get a trend of my sump water level. Set an alarm if the sump gets down below what 4 gallons would be. That way I know my fresh salt water line or pump isn’t putting the new saltwater in the tank because I will get an alarm. That should prevent this issue of the ato filling my tank with fresh water if the new salt water part of the auto top off fails. I have never done auto water changes before so I don’t know exactly how it works, but is there anything I’m missing? Should work right?