Can small, daily water changes replace large weekly ones?

[PB_Smith]

Hate quoting myself, but it really is this simple;

Bottom line is if your critters are all doing good, healthy and happy and so are you, than whatever regime you have established is working.
There are no rules carved in stone about fish keeping, just common sense.

 

[Luananeko]

He generates 15ppm weekly rather than daily.

The 15 ppm daily was just an example to show the math on how 5% changes work out vs their equivalent amount in one go on a pure percentage basis. I didn't see where they stated how much their ppm goes up weekly or daily, so I picked a number that was easy to work with as an example. Even swapping variables out, the percentages comparing the two water change schedules are consistent.

 

[Mebbid]

The 15 ppm daily was just an example to show the math on how 5% changes work out vs their equivalent amount in one go on a pure percentage basis. I didn't see where they stated how much their ppm goes up weekly or daily, so I picked a number that was easy to work with as an example. Even swapping variables out, the percentages comparing the two water change schedules are consistent.

If you're doing 5% water changes daily then presumably the nitrates would level out at 50ppm. It'll be removing 2.5ppm daily which is what's being produced.

 

[Mama Karoti]

Okay.... Assuming you start with 50 nitrates at the start of the week and your fish generate 15 nitrates per day. Since your fish generate 105 nitrates during the week (7 days x 15 nitrates a day), and you started at 50, the nitrates would have been at 155 if you had done no water changes.

Since your fish generated 105 nitrates during the week (7 days x 15 nitrates a day), and you started at 50, the nitrates would have been at 155 if you had done no water changes.

A 5% water change would do this (rounding to nearest .01 and assuming no other sources of nitrate reduction):
Day 1: 50 nitrates - 2.5 = 52.5
Day 2: 52.5 + 15 = 67.5 - 3.38 = 64.13
Day 3: 64.13 + 15 = 79.13 - 3.96 = 75.17
Day 4: 75.17 + 15 = 90.17 - 4.51 = 85.66
Day 5: 85.66 + 15 = 100.66 - 5.03 = 95.63
Day 6: 95.63 + 15 = 110.63 - 5.53 = 105.1
Day 7: 105.1 + 15 = 120.1 - 6 = 114.1

That's roughly a 26% reduction, compared to a 35% reduction if you did the same amount of water changes all in one go.

This is correct. My math included fish that didn't poop during the week I did the calculation. Lol. So yes, if 26% WWC is the OP's target, then 5% a day is equivalent.


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[Luananeko]

If you're doing 5% water changes daily then presumably the nitrates would level out at 50ppm. It'll be removing 2.5ppm daily which is what's being produced.

15 a week would actually be roughly 2.14 nitrates added each day, not 2.5, so the 5% daily would overall reduce nitrates towards zero over time. Is 15ppm a week a reasonable number though? I've tried plugging different numbers in to see how the percentage differences change, and it looks like there is a point on where 5% either neutralizes the nitrate creep completely or it falls behind like my calculations showed. This seems like it only happens in situations where you're running with a very light stock and feeding schedule, or where you have other sources of nitrate reduction (purigen in filter, lava rock decor, live plants, etc) to keep the daily nitrate creep low.

 

[enrgizerbunny]

15 a week would actually be roughly 2.14 nitrates added each day, not 2.5, so the 5% daily would overall reduce nitrates towards zero over time. Is 15ppm a week a reasonable number though? I've tried plugging different numbers in to see how the percentage differences change, and it looks like there is a point on where 5% either neutralizes the nitrate creep completely or it falls behind like my calculations showed. This seems like it only happens in situations where you're running with a very light stock and feeding schedule, or where you have other sources of nitrate reduction (purigen in filter, lava rock decor, live plants, etc) to keep the daily nitrate creep low.

Eh. It's kind of like a half life, because the reduction gets smaller every day. If OP is stocked lightly enough to be able to remove the nitrates produced daily with 5%, why not do a 10% change daily and be done with it?

I think it is experimentation time with this. I have a very lightly stocked tank, I'll compare the two methods and see what my results are.
The fact of the matter is that there are so many variables in play here as to whether it will work or not. The only solution would be to try and test. Having increased nitrates of such a low concentration won't hurt the fish and the solution is known and simple.

OP, if you don't go for it then I will and I'll report back in 2 weeks.

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[jetajockey]

I don't really get why someone would rather do a wc every single day instead of just one a week.

 

[Luananeko]

I don't really get why someone would rather do a wc every single day instead of just one a week.

I don't either, especially not when there's been so many suggestions here for far easier water change methods then the bucket brigade. But it's been an interesting comparison discussion at the very least.

 

[Mebbid]

I don't really get why someone would rather do a wc every single day instead of just one a week.

That's easy.. So you can avoid this picture which is what I had to do on a regular basis when my water changer broke.

 

[enrgizerbunny]

These are my results after my 50% weekly change. I will perform 10% changes daily for the next week and post results once one week had elapsed.

Results before are on the left, after on the right.

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[PB_Smith]

These are my results after my 50% weekly change. I will perform 10% changes daily for the next week and post results once one week had elapsed.

Results before are on the left, after on the right.

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that is the incorrect way to read the test. you need to hold the vial against the white portion of the card, otherwise it gives a false reading of being too light.

 

[enrgizerbunny]

that is the incorrect way to read the test. you need to hold the vial against the white portion of the card, otherwise it gives a false reading of being too light.

I don't have 6 hands.
What does a white piece of paper and the white card make a difference though? This isn't rocket surgery.

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[PB_Smith]

when held against the card next to the corresponding chart (as per instructions) the color in the vial is darker and is a more accurate reading considering that is what they are calibrated for.
Try it.

but I am curious as to the results of your experiment.
will be following

 

[allysonwonderland]

These are my results after my 50% weekly change. I will perform 10% changes daily for the next week and post results once one week had elapsed.

Results before are on the left, after on the right.

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Awesome, can't wait to see what happens! Unfortunately I can't participate in this experiment quite yet, as I'm going on a 10 day vacation next week, but I'll take what you find out into account and post my own results when I get back, if this thread is still active.

As for those suggesting a python, I think that's the route I'm going to take when I can I just don't have the cash to drop right now. As I explained in my first post, it's just less of a hassle for me to bring one bucket back and forth per day, rather than 5-6 in one sitting. It's getting to the point where I dread water change day, it's time consuming and taxing on my back. I don't have any upper arm strength!

 

[jetajockey]

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This is what I use in conjunction with a drinking water safe hose. If you go this route try to find a 'neverkink' or reinforced hose, as the cheap drinking water hose collapse on themselves in short order.

Depending on what tanks I'm doing, sometimes I just run the hose outside into the garden and then start a siphon, so no special equipment needed in that situation apart from the hose and a clear siphon tube.

 

[enrgizerbunny]

Awesome, can't wait to see what happens! Unfortunately I can't participate in this experiment quite yet, as I'm going on a 10 day vacation next week, but I'll take what you find out into account and post my own results when I get back, if this thread is still active.

As for those suggesting a python, I think that's the route I'm going to take when I can I just don't have the cash to drop right now. As I explained in my first post, it's just less of a hassle for me to bring one bucket back and forth per day, rather than 5-6 in one sitting. It's getting to the point where I dread water change day, it's time consuming and taxing on my back. I don't have any upper arm strength!

This experiment was cancelled due to the holiday weekend, 14 hour work days, death in the family, and the addition of hydrilla verticillata to the tank (similar to anacharis aka egeria). It was a busy weekend/last 4 days.

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