The Ultimate Water Change??

[Diesel]

As I was talking with Mike Paletta on the phone and we discussed what is the best % for a reef tank to change out water and how many times.
We agreed that this needed a discussion on it's own.
This is not about what kind of salt you use or the equipment to do so.
More like weekly or daily or not at all as I sometimes read.
Mention the total gallons you run on your system and bio-load will help too as what kind of reef, SPS, softies or mix.
Going deep down into chemistry to explain why you doing daily or weekly WC might be overkill but if it makes sense to all, Please in English that we all can understand, why not.

I do a WC twice a week on Monday and Friday both days I change 10 gallon so we talking 20 gallon a week on my 280 (202 DT and about 80 gallon sump)
The WC will take me not more than 10min and that is with two jugs of 5 gallon each.

 

[candcreef]

I do a WC once a week (15 gallons) on a 175 system....150 gallon tank with 25 gallon sump....I have nine fish and run a predominately sps tank with some lps....the WC takes me approximately 15 min to perform....

Conan

 

[Acroholic]

I do a 1% daily (4.6 gallon) water change via a CP Masterflex dual head peristaltic pump setup. This percentage is suggested by Randy Holmes Farley, and what he does on his personal reef tank.

 

[wrasseluver]

I do 10 gallons weekly and once a 20 gallons. It's a 100 with a 25 gallon sump. It's 90% lps and heavy feed for the 14 small fish I have. It takes me 20 mintues because I test before and after the water change.

 

[cope413]

7g every 6 days on my 40g breeder with 28g sump. I used to do 10g every other week and tried daily 2g changes for 30 days. The results were fantastic but it was too much effort for daily changes. I backed off and landed on this. I've got 4 fish, and mostly lps with some sps. I like to feed a lot too.

 

[melev]

I do a 1% daily (4.6 gallon) water change via a CP Masterflex dual head peristaltic pump setup. This percentage is suggested by Randy Holmes Farley, and what he does on his personal reef tank.

I have the same gizmo and have never enabled it to this day. Just not comfortable connecting my 250g's of saltwater to a small hose and expecting it to work out fine. lol

 

[melev]

My system has a total water volume of 450g, and I do a 50g water change occasionally. It's about once every six weeks, probably. It's a decent bioload, and I run biopellets; hence I feed often.

 

[Acroholic]

I have the same gizmo and have never enabled it to this day. Just not comfortable connecting my 250g's of saltwater to a small hose and expecting it to work out fine. lol

A Masterflex pump is better built and less prone to breakdown than probably any piece of mechanical equipment you or I have on our reef tanks.

The tubing used with these pumps is a brand called Phar-Med, manufactured by the same company that makes Tygon. It is FDA approved for use in Medical and Food applications. You use two lengths about 7 inches long each for the Easy Load Heads, then barbed fittings for normal vinyl tubing into and out of the tank. I change the drip set out once every 6 months or so.

But you have to be comfortable with what you use or do not use, so to each his own, I say. I am quite comfortable having this piece of equipment on my 465 gallon SPS reef.

 

[melev]

A Masterflex pump is better built and less prone to breakdown than probably any piece of mechanical equipment you or I have on our reef tanks.

The tubing used with these pumps is a brand called Phar-Med, manufactured by the same company that makes Tygon. It is FDA approved for use in Medical and Food applications. You use two lengths about 7 inches long each for the Easy Load Heads, then barbed fittings for normal vinyl tubing into and out of the tank. I change the drip set out once every 6 months or so.

But you have to be comfortable with what you use or do not use, so to each his own, I say. I am quite comfortable having this piece of equipment on my 465 gallon SPS reef.

I just have to quit making excuses and plumb it all in. It's the worst-case scenario that made me paranoid. Not the machine going wrong, merely that my tubing will pop loose and send saltwater into a nearby outlet. Murphy never sleeps, after all.

Your tank looks great!

 

[MrsDragon]

I would love to know if you guys use fresh saltwater or make up your own. I'm a newbie and I have a 55gal cube with a canister filter. Only been set up about 3 months. I would love more info on how much and how often I should be changing because it's so different from my planted freshwater tanks.

 

[joeyhatch11]

I do a 5g weekly WC's on my 45G total system (33L with 20L sump). I have 6 fish and feed small amounts daily. I also Vodka dose and that has helped the tank tremendously!!! I did however try doing 5G bi-weekly water changes but I found I was spending more time cleaning the glass during the week as well as changing out my filter floss too often. So back to weekly's I went and couldn't be happier.

 

[Keithcorals]

What I don't understand is how small water changes can keep up with what is depleted. In a system with only soft coral it will have a better chance but especially in an SPS system more than 10 percent of some stuff can be depleted in a day. In my SPS system of around 200 gal the alk will drop one point a day the only way I could keep it up with water changes would be to change 100% every day. The math doesn't add up. It takes 6 50% water changes to replace close to 99% of the water in a tank so if you did a weekly 50% water change it would take you 6 week to have changed all the water from before the 6 weeks but you would still have depleted elements and trace elements over the six weeks. The answer has to be replacing what it being removed in a more efficient way than water changes. Maybe in the future we will have the technology to test for all of what is missing and only add what we need. I'm only talking about water changes for replacing elements because my system never has nutrients get above acceptable levels.
I do so few water changes I couldn't even tell you how often and almost never more than 5-10%

 

[Diesel]

What I don't understand is how small water changes can keep up with what is depleted. In a system with only soft coral it will have a better chance but especially in an SPS system more than 10 percent of some stuff can be depleted in a day. In my SPS system of around 200 gal the alk will drop one point a day the only way I could keep it up with water changes would be to change 100% every day. The math doesn't add up. It takes 6 50% water changes to replace close to 99% of the water in a tank so if you did a weekly 50% water change it would take you 6 week to have changed all the water from before the 6 weeks but you would still have depleted elements and trace elements over the six weeks. The answer has to be replacing what it being removed in a more efficient way than water changes. Maybe in the future we will have the technology to test for all of what is missing and only add what we need. I'm only talking about water changes for replacing elements because my system never has nutrients get above acceptable levels.
I do so few water changes I couldn't even tell you how often and almost never more than 5-10%

Keith, you made a good point here.
Most reefers dose some kind of nutrients in their tank, just to name a few, Amino's, potassium, and the big three ALK, CAL and MAG.
Not to mention that if you have fish, they bring also on a daily basis nutrients in your system.
Not saying that your system is off, others that JD will not look that good.
My JD that a gave away to a friend wasn't doing that great in my tank, but heck that's another topic.

 

[MrsDragon]

See, this is why this sort of information is so useful. I thought water changes were for keeping nitrate levels down, which is the main reason I need to do water changes on my freshwater tanks. I am now having a brief panic attack but will be all good.

 

[YHSublime]

I have a 150 gallon, with a 20 gallon plumbed in, and probably a 40 gallon sump. Total water volume is probably around 180 with rock and sand, etc.

I am predominantly SPS (with some LPS) and I am dosing as mentioned above for calk, alk, and mag. I change 40 gallons every two weeks, like clockwork. My growth has been sublime, and my levels stay consistent. IMO it's far more important to be consistent with whatever you do, and your corals will respond well.

 

[jokervueboi]

I have 46g dt and 40 sump. I do 10g water change every Saturday. I have mostly lps and softies. 9 small fish like clowns and neon gobies.

 

[tyler1503]

I have 3 tanks running at the moment. A 5gal, a 24 and a 1ft cube freshwater tank.
In the 5 gal I have 2 sand gobies and some LPS and softies. I used to do somewhere in between 1-5% daily. I had great colour and steady growth on most things. But now I only do about 15-20% monthly and have seen much slower growth in the corals that were growing well before, but much faster growth in those that were slow before. I need to find a happy medium. I speculate maybe 10% a week would be a good start for that tank.
I almost never do water changes on the 24 fowlr and if I do, I do about 15%. I'm passed the algae blooms and have pretty low phosphate and nitrate, so I have no real need to do them weekly or whatever. Being a fowlr I also don't have to worry a whole bunch about things like cal alk and mag.
The freshwater tank gets a 25% water change when the filters flow rate drops to the point the plants in the other end of the tank barely move.
I really need a better schedule for my water changes. When the 120 is up and running I've planned 5gal water changes twice a week. I've already worked it in around my work schedule.

 

[watchguy123]

What I don't understand is how small water changes can keep up with what is depleted. In a system with only soft coral it will have a better chance but especially in an SPS system more than 10 percent of some stuff can be depleted in a day. In my SPS system of around 200 gal the alk will drop one point a day the only way I could keep it up with water changes would be to change 100% every day. The math doesn't add up. It takes 6 50% water changes to replace close to 99% of the water in a tank so if you did a weekly 50% water change it would take you 6 week to have changed all the water from before the 6 weeks but you would still have depleted elements and trace elements over the six weeks. The answer has to be replacing what it being removed in a more efficient way than water changes. Maybe in the future we will have the technology to test for all of what is missing and only add what we need. I'm only talking about water changes for replacing elements because my system never has nutrients get above acceptable levels.
I do so few water changes I couldn't even tell you how often and almost never more than 5-10%

You do indeed make some interesting points. We do know some things are depleted rapidly from water in an sps tank, alk, ca and mag. But what else. There are lots of test kits but I have two issues with them 1) they are generally crummy (some better than others) 2). What other "things" should we be testing regularly? I do indeed test alk, ca, mag regularly and less frequently nitrates and phosphates. My calcium reactor keeps up with the the alk, ca and mag (almost), and my skimmer, gfo and typical 5% weekly water change keep up with nitrates and phosphates

So what I am interested in are the things I cant measure or can't measure well. I do not want either an accumulation of something harmful or depletion of something essential.

Ok, we know there are tanks with frequent water changes and those with perhaps no water changes. And we know both can thrive but what might be optimal. Is there a magic ( or perhaps more ideal water change) percentage that would tend to keep "more" parameters in an ideal range. Maybe fish food and the resultant poo add deficient elements in an adequate range. Or does some unmeasured element accumulate or disappear that would be replaced by water changes

I don't think water changes are the best choice for alk, ca and mag. I think dosing or ca reactor is most likely required for those. So I am curious what water amount of water changes will optimize an sps tank long term.

 

[Keithcorals]

Keith, you made a good point here.
Most reefers dose some kind of nutrients in their tank, just to name a few, Amino's, potassium, and the big three ALK, CAL and MAG.
Not to mention that if you have fish, they bring also on a daily basis nutrients in your system.
Not saying that your system is off, others that JD will not look that good.
My JD that a gave away to a friend wasn't doing that great in my tank, but heck that's another topic.

I dose fuel daily and have over 30 fish that I feed daily. I do what I call a food storm at least once a day.
My phosphate is 0.000-0.009 on Hanna phosphorus checker and it has been verified and reverified at that level my nitrate is at or below 0.2

 

[Keithcorals]

What would be really nice is a calculator that would tell you how many water changes it will take to replace all the water. So you could then decide how often all the water should be replaced. I would like to know this for my bio cube. I do water changes on it but not often if I new the amount I needed to change to keep the water in it 100% replaced every 3 months I'd most likely do it.

Anybody good at math know how to build this type of calculator?