A novel reefing method: water change (only) method

[encrustingacro]

In this method you use water changes and water changes ONLY to keep your tank running. You don't test for anything--if anything seems off in your tank, just do a water change. No dosing either--if you want to keep up with major and minor element uptake, you just do small daily water changes using an automated doser. What are your opinions on this method?

 

[Dburr1014]

In this method you use water changes and water changes ONLY to keep your tank running. You don't test for anything--if anything seems off in your tank, just do a water change. No dosing either--if you want to keep up with major and minor element uptake, you just do small daily water changes using an automated doser. What are your opinions on this method?

Most likely minor/major elements won't keep up. Unless, of coarse, your doing big water changes.
On a big tank, no thanks.

 

[Uncle99]

Short term fine. I think in time, it will be a disaster.
Not knowing your water in terms of parameters, buffering and nutrients maintenance going to catch up.

And very expensive.

 

[codycolina707]

In this method you use water changes and water changes ONLY to keep your tank running. You don't test for anything--if anything seems off in your tank, just do a water change. No dosing either--if you want to keep up with major and minor element uptake, you just do small daily water changes using an automated doser. What are your opinions on this method?

Seems like alot of money for big tanks kalk is pretty cheap id have to do like 10 to 15 gallons atleast a day to keep up with alk I do 3 gallons auto daily and that doesn't change much of anything

 

[Slocke]

You’d have to add elements to the water changes to avoid a slow reduction in them from uptake of organisms and potentially precipitation.

 

[blecki]

Water changes can't raise levels above what's in the salt mix. Some mixes have higher than desired calcium, alk, magnesium for this reason, but not all.

But I've seen it very successfully done with little nano tanks of like 3 gallons where they get a 100% water change each time.

 

[Randy Holmes-Farley Verified Community Expert]

In this method you use water changes and water changes ONLY to keep your tank running. You don't test for anything--if anything seems off in your tank, just do a water change. No dosing either--if you want to keep up with major and minor element uptake, you just do small daily water changes using an automated doser. What are your opinions on this method?

It obviously works, and will take very large daily changes in a tank with significant alk demand.

 

[exnisstech]

While this may work on pico and some smaller nano if the salt mix has what is needed I don't think it's a solution for larger tanks. I tried it early on only because I didn't know better and I had a lot of unexplained corals deaths many easy coral like xenia and Cespitularia.

 

[rtparty]

For very small tanks, it works wonderfully. I first saw the idea from Jake Adams and he ran a small tank this way for a long time. I setup a 7.5g tank and ran it this way as well. It wasn't true 100% water changes since I needed to leave some water for the fish. I ran this tank for close to a year on weekly 90% water changes. Everything did great.

This is where I came to appreciate quality salts that are clean and consistent.

 

[d2mini]

In concept, yes.
In practice, usually not.

Any decent amount of coral will remove major elements faster than you can replace them, unless you are doing massive water changes, making it harder to maintain than if you just supplemented with a doser or some other mechanical means.

A tank under 10g would be much easier, but you will still need to be careful with parameters like temperature. Swings of any kind are bad for sensitive species.

 

[SliceGolfer]

Oh, so reefing like we did in 1990

 

[Troylee]

I like it! I will always do changes no matter bottles they have on a shelf any more… I do have to add some alk and calcium cause my demands super high but I count on a wc for everything else!

 

[schooncw]

This is a section of my LPS dominant 120. I do a garbage pail WC every 2-4 weeks with decent salt and that’s it.
I do check PO-never below 1.0-and NO3-45-75-but no bad algae or issues.
System is overstocked and overfed and is 35 or so years old.

 

[schooncw]

This is a section of my LPS dominant 120. I do a garbage pail WC every 2-4 weeks with decent salt and that’s it.
I do check PO-never below 1.0-and NO3-45-75-but no bad algae or issues.
System is overstocked and overfed and is 35 or so years old.

 

[RelaxingWithTheReef]

In the very early days of reefing this was the dominant method. Testing was very limited, calcium and alkalinity requirements and supplementation were poorly understood, and trace elements were not even discussed. (Well, maybe strontium Lol)

I current run an extreme pico tank that consumes about 4 dKH of alkalinity per day. In this case even a 50% WC per day would result in an extreme daily alkalinity swing that would likely lead to a long term failure.

Success depends on what your corals are removing from the tank, verses a water change schedule that is practical in the long term to exactly replace what's being removed.

Softies = Likely success
Limited quantity of hardy LPS or SPS = Possible success
Lots of LPS and SPS = Not likely to be successful

 

[Randy Holmes-Farley Verified Community Expert]

FWIW, I show what what changes of various sizes can accomplish here:

Water Changes in Reef Aquaria by Randy Holmes-Farley - Reefkeeping.com

for example, alk demand of 0.56 dKh per day:

Alkalinity as a function of time when performing very large daily water changes of 0% (no changes), 5%, 10%, 15% and 30% of the total volume EACH DAY. In this example, alkalinity is present at 4 meq/L (11 dKH) at the start and is depleted at a low rate of 0.2 meq/L per day.

Conclusion
Water changes are a good way to help control certain processes that serve to drive reef aquarium water away from its starting purity. Some things build up in certain situations (organics, certain metals, sodium, chloride, nitrate, phosphate, sulfate, etc.), and some things become depleted (calcium, magnesium, alkalinity, strontium, silica, etc.). Water changes can serve to help correct these imbalances, and in some cases may be the best way to deal with them. Water changes of 15-30% per month (whether carried out once a month, daily or continuously) have been shown in the graphs above to be useful in moderating the drift of these different seawater components from starting levels. For most reef aquaria, I recommend such changes as good aquarium husbandry. In general, the more the better, if carried out appropriately, and if the new salt water is of appropriate quality.

Calcium and alkalinity, being rapidly depleted in most reef aquaria, are not well controlled, or even significantly impacted by such small water changes. In order to maintain them with no other supplements, changes on the order of 30-50% PER DAY would be required. Nevertheless, that option may still be a good choice for very small aquaria, especially if the changes are slow and automatic.

 

[brandon429]

90% of all pico reefs on the planet use this method


it's size relative

not practical for most large tanks unless the ca/alk demand is in line with the replenish rate

but for a 1-5 gallon tank? best method known. I'm on year 19 using solely this method in a fishbowl reef with sps in it.

 

[KrisReef]

90% of all pico reefs on the planet use this method


it's size relative

not practical for most large tanks unless the ca/alk demand is in line with the replenish rate

but for a 1-5 gallon tank? best method known. I'm on year 19 using solely this method in a fishbowl reef with sps in it.

100% of natural reefs use water changes only, but the water content also changes according to currents, seasons, tides, and biorythmic changes in concert with solar and lunar cycles, but zero parameter tests as far as I understand.

 

[felda001]

I did this all the way to 2013. When I was in Southern California I got the water free from Scripps aquarium by far the best results I've ever had with a reef. I didn't even have a test kit. Just 10% weekly water changes.

 

[OrionN]

I only do 10% water change every 2 weeks but do need to add Ca and Alkalinity for my 40 gal office tank. For nano tank, I think water in the order of 75% weekly will surely works.
Use a 5 gal bucket to mix salt water is great. I use RO water for water change, either IO or RC for salt mix. Easy maintenance. I only have two clown fish in this tank, maybe will add a third fish.