Water Changes, Daily or weekly?

pokerdobe · Mar 24, 2017

wkscott said:
If you have 50 gallons in circulation, 1.5 gallons would be 3 % per day. This in no way compares to the benefits of the 25% weekly water change. For example, if your nitrates are at 100ppt. a 3% water change will only reduce them to 97ppt. On the other hand, a 25% water change would reduce them to 75ppt. Do the math on the 3% water change and see just how many days it would take to reduce your nitrates by 25ppt.

I did the math and it's definitely not my strong suit, but I think the difference is marginal.

Assuming 50 gallons of water volume with a starting point of 10ppm nitrate with 10ppm nitrate production per day, here's how the math broke out for me:

3% Daily
Day 1: 10 PPM
Day 2: 19.7 PPM ((10PPM-(10PPM x .o3))+10PPM)
Day 3: 29.109 PPM ((19.7PPM-(19.7PPM x .03))+10PPM)
Extrapolated to Day 8, you would have 64.005 PPM of No3.

25% Weekly
Assuming w/c is done on Day 7, on Day 8, you have 62.5 PPM of No3.
Day 1: 10
Day 2: 20
....
Day 8: ((70PPM-(70PPM x .25))+10PPM)

So at Day 8, you have 64 PPM vs 62.5 PPM

SantaMonica · Mar 26, 2017

If determined to do them, consider a continuous system using a peri pump.

NanaReefer · Mar 26, 2017

I've been doing 15% bi-weekly WC on my 40B/20L sump for 3yrs. Has worked out great.

nvert · Apr 27, 2017

I use a Stenner dual peristaltic pump to change out 4gal of water daily on my 120g display + 30g sump. I mix new salt water (HWMarineMix) in a 44g Brute can every two weeks. I was getting lazy doing regular monthly water changes with siphon and buckets so I went the automated route. Been a year now and I won't go back to carrying buckets ever again! Now that my tank is maturing, I'm about to set the water change system to 2gal a day change

ReeferMadnessfragandco · May 23, 2017

Indo Nano said:
So I've been doing 25% water change weekly on my 50g custom build. Because of my busy schedule, I was think of just doing daily water changes, if my math is right I could meet the needs of a weeks worth if I did one and a half gallon water change daily.... I just want to ask what R2R community advise would be on this topic, please give me your input. If you do daily water changes please tell me how it works for you. Thanks to those that will help!

Once a week is more than good!! And mine you most people only do 10% weekly...

BlueCursor · May 28, 2017

I use Apex DOS for daily 1% water changes. I will never go back to any other method. Now, I never have to adjust pH, Ca, Mg, Alk, etc. I don't even adjust temp! My corals have never been happier and life has never been easier with regards to water changes.

Here is a link to a calculator that shows you equivalent water changes: https://www.hamzasreef.com/Contents/Calculators/EffectiveWaterChange.php

This calculator correctly shows that a 1% daily water change is equivalent to a 26% monthly water change.

Gord · Jun 1, 2017

i tried this method a few years ago and was actually thinking about doing it again. if the goal is to maintain stability and not have ups and downs within your tank i think its a great way of doing things. i actually found it alit easier to do small amounts daily rather than big weekly changes. i could just mix up the small amount and put it in the sump and then take the bucket and scoop out that amount from dt. done.

David Cher · Jun 1, 2017

BlueCursor said:
I use Apex DOS for daily 1% water changes. I will never go back to any other method. Now, I never have to adjust pH, Ca, Mg, Alk, etc. I don't even adjust temp! My corals have never been happier and life has never been easier with regards to water changes.

Here is a link to a calculator that shows you equivalent water changes: https://www.hamzasreef.com/Contents/Calculators/EffectiveWaterChange.php

This calculator correctly shows that a 1% daily water change is equivalent to a 26% monthly water change.

how do you use this calculator ? just punch in the tank volume and the water change volume and press on the calculate right ?

wmo168 · Jun 27, 2017

p7willm said:
I do daily water changes, but I take the easy way out. I have a DOS that sucks out 4 liters and sticks 4 new liters in every day at 1pm. I only make salt water every 10 days.

1pm it start, how long does it takes to finish the 1 lilter? I believe you want it run at 1pm so you don't hear the noise..

Do you setup float sensor to stop incase the NSW is low or OSW is full just in case?

biecacka · Jul 12, 2017

I too have been contemplating auto water changes. Now my set up is relatively easy but I really like the no work aspect of it. My parameters are pretty stable so it's more just for the water change aspect and ease of it.

Corey

vinny110 · Jul 20, 2017

I do water change every 2 weeks, when I first started. Now its every month. I think as your tank develops it cleans itself and you do less water changes.

Willragan · Jul 22, 2017

Ive done both daily and weekly water changes as well as monthly on fowlr systems. Ive seen success with all 3. Its all about stability in water chemistry imo. However you can achieve stable and correct parameters is the right way to do it. You can get away with very few water changes with a light fishload and dosing or you can do more water changes with less dosing imo. I see merit in small daily changes because you are altering parameters more slowly with less water changes in intervals but if you can achieve super close parameters in the new water more can be safely changed at a time. So i guess my whole point is there are many ways to achieve the same outcome and i dont know that any one is the best way. Imo ideal parameters for most organisms we consider desirable are: salinity 1.026, calcium 450, alk 8.5, magnesium 1500, ammonia and nitrite 0, nitrate 5, phosphate barely detectable. However one can achieve as close to those parameters with the smallest possible swings is the right way imo. If maximum growth is the goal i can also see where raising alk and nutrients in the correct ratio could be considered beneficial. But has to be a balance. Higher alk without raising nutrients equals pale tips and higher nutrients without raising alk equals brown corals imo. Even skeletal growth and flesh growth requires balance i believe.

SantaMonica · Jul 30, 2017

I think as your tank develops it cleans itself and you do less water changes.

Yes, it the natural periphyton on the rocks that does this.

Ashish Patel · Jul 30, 2017

depends on kind of tank softie tank can use the dirty water nitrates is a good indicator of how much to change - one every 4-8 weeks is good. SPS generally have low nutrients to start with so trace element replenishment and detritus removal is the goal. Overtime when a tank is packed with corals I feel a nice daily water change could be a good solution to those old tank syndrome problems.. Not sure if this made sense but this is my thoughts

Donovan Joannes · Aug 13, 2017

Build your simplest filtration system, let nature deal with the rest. Once matured, say goodbye to water changes. We tend to complicate the process, scratch our head when problem arise. Too many items doing the exact same thing makes my head spinning.

Velcro · Aug 13, 2017

wkscott said:
If you have 50 gallons in circulation, 1.5 gallons would be 3 % per day. This in no way compares to the benefits of the 25% weekly water change. For example, if your nitrates are at 100ppt. a 3% water change will only reduce them to 97ppt. On the other hand, a 25% water change would reduce them to 75ppt. Do the math on the 3% water change and see just how many days it would take to reduce your nitrates by 25ppt.

This isn't actually accurate. Here's the math to prove it. The one thing that I changed is your 25% to 21% (3%x7days) to make it fair. The difference isn't THAT extreme in the end and there's more stability in all the other parameters doing daily vs weekly.