5%, 10%, 20%? Water change schedule. Opinions!

[curtismaximus]

I was wondering if there is a "best" schedule for water changes?
5% twice a week?
10% once a week?
20% once every two weeks?
Other?

Is there a difference or does it really matter?
Is it not a big deal as long as you do them consistently?
Im dosing Vodka btw.

Thanks!

 

[ringo®]

I'm a fan of smaller, more frequent changes.

 

[wildernets]

I do about 15% every 10-14 days. It has worked for me so I stick with it. Nothing scientific about the decision though.

 

[jennm]

The short answer: It depends.

The longer answer: Smaller, more frequent water changes, change more net water over time. They also keep your parameters more stable, since nutrients don't have as much chance to build up, so if you plotted, say, nitrates, on a graph, you wouldn't see huge peaks and valleys on the graph.

The answer to what is best for your particular tank (or anyone's), depends on many factors, but testing the water regularly (ie weekly) will tell you if you are changing enough water.

If your bio load is light, perhaps 10% per week will do. If it's heavy, maybe 20% per week might not be enough.

Unless there's an immediate crisis, I don't usually suggest doing more than 20% at a time. Changing too much at once will upset the ionic balance and can result in a diatom bloom or other imbalances that can become as problematic as whatever you were trying to correct.

So smaller amounts, more frequently tends to work out best in the long term - backed up by testing to make sure water quality is maintained.

Once nitrate gets ahead of you, it takes quite some work to get it back under control. The best cure is prevention.

Jenn

 

[curtismaximus]

I figured testing would be the eventual answer. I just wondered if one was better than the other.

Side note... cant more frequent water changes be a negative also? Especially in smaller tanks?

 

[jennm]

Anything excessive would be bad, IMO. But if we're talking percentages, the same percentage changed regularly in a small tank, shouldn't be any better or worse than in a large one. In fact, the smaller tanks are the ones more vulnerable to nitrate spikes, because the smaller water volume is less forgiving. I suppose changing too much would keep a small tank in a state of imbalance. So yes, you can over-tinker. I've seen that quite a bit with people chasing numbers when the existing numbers were "ok". (IE calcium, pH) Stability is more important than a "450" (CA) or 8.3 (pH) I'd rather see a tank with a solid 390 than one fluctuating up and down. Same with pH, I'll take a solid 8.1 versus yo-yoing from 8.0-8.3.

A good dose of common sense goes well in that regard.

Jenn

 

[acroholic]

I do a 1 percent daily change via an auto water changer.

If you are doing it manually, I would look at 10 percent every two weeks, or if you are willing to do weekly, do 5 percent a week.

Be honest with yourself in what you are willing to do regarding your water changes. Whatever amount and whatever frequency you decide to do, stick to it. Better to do less frequent, but regular, changes, than play catch up once a month with a single large change, at least IMO. Keeps the stability of the system better.

 

[ralph atl]

imho, there is nothing better for the most difficult fish including Tamarin Wrasses and the most difficult of the Leopards, Kuiter's & Choati's AND corals such as SPS & a few species of LPS than large weekly water changes of up to 30%-35% as long as it is exacly the same salinity & KH (which would relate to ph). There are only a few salt mixes that do this without additives, Salinity being the best, Seachem Reef, Tropic Marin, and maybe another...

This removes the most waste, and adds the most trace to maintain...
most importantly, adds O2 in a huge way!

 

[fidofence]

Ralph is extreme but if it works for him then great!

 

[ringo®]

Adisport;932209 wrote: Does anyone else support this opinion? .

Sure. You just have to take extra precautions to make sure you don't throw anything too out of whack.

 

[Reefplumber13]

Question. . I have a 20 gallon and I do about a 5 gallon change every week.. is that too much or is it good

 

[nickh06]

I do 10% every week, haven't had any major issues.

 

[heathlindner25]

Adisport;932209 wrote: Does anyone else support this opinion? These seems very extreme to me. I like the idea of topping off trace minerals, removing a lot of waste and adding O2 but I tend to agree with Jenn that even the most compatible water still will cause an imbalance, chemically, if you do such a large change.

I do!

 

[declanisadog]

Adisport;932209 wrote: Does anyone else support this opinion? These seems very extreme to me. I like the idea of topping off trace minerals, removing a lot of waste and adding O2 but I tend to agree with Jenn that even the most compatible water still will cause an imbalance, chemically, if you do such a large change.

You can't argue with his results. I personally have always done 20% weekly.

 

[raz0945]

I feed heavily and do a 20% weekly water change, if I have a problem I might do a small one in 2-4 days. Holley

 

[skriz]

Adisport wrote: Does anyone else support this opinion? These seems very extreme to me. I like the idea of topping off trace removing a lot of waste and adding O2 but I tend to agree with Jenn that even the most compatible water still will cause an imbalance, chemically, if you do such a large change.

Water changes correct water issues and imbalances, not cause them. large water changes are great. I have never seen corals and fish happier than after a large wc.

Assuming you're using a quality salt mix, you won't need to adjust Ca, etc. Even with a deficient salt, your calcium reactor should handle it.

 

[snowmansnow]

IMO you can tinker too much with your water.
I change 5g a month on 140g of water :/

B

Edit: reason is that if I start changing more my colors start to wash ....

 

[heathlindner25]

SnowManSnow;932419 wrote: IMO you can tinker too much with your water.
I change 5g a month on 140g of water :/

B

Edit: reason is that if I start changing more my colors start to wash ....

everybody's tank is different, and you have some great looking coral,but that's surprisingly low amount of water changes...lol

 

[curtismaximus]

SnowManSnow;932419 wrote: IMO you can tinker too much with your water.
I change 5g a month on 140g of water :/

B

Edit: reason is that if I start changing more my colors start to wash ....

5gal a months... Thats almost hard to believe! Do you dose or use a reactor?

 

[jennm]

I agree that everybody's tank is unique.

I also agree that you can over-tinker with a tank - I've seen it many times, and the tinkerer never manages to find the numbers he/she is looking for and drives themselves crazy with it. My advice at that point has been, "Leave it alone". Feed it, do regular water changes, but quit dosing for a couple of weeks and let it find its equilibrium and quit tampering with it. Almost every time, when left more or less alone, levels balanced out, and then any necessary dosing could be fine tuned over the next couple of weeks without much effort.

As for the happy corals after a large water change - part of that *could* be that when people do a huge water change, they usually go all in and stir up all the crap and detritus, and that will most certainly kick corals into 'feeding mode' with all the particulate stirred up. Doesn't have to be a large water change to achieve that - heck, doesn't have to be a water change at all - just the act of agitating the substrate or fanning the rocks will kick up the crud and cause the corals to go into feeding mode.

Jenn