Why a weekly 50% WC is better than two weekly 25% WCs

[ScatMan]

THe point is some schmuck is going to take this "data" and start up with the "less is more" yodeling instead of " more is better" approach. You are justifying every slacker who doesn't do regular water changes in their minds atm... As Jose pointed out it's a very slim margin...

don't blame the data for the actions of "some schmuck" who doesn't understand how to do a water change. the information provided by op is only going to help improve water quality. if a "slacker" doesn't know how to interpret the data, that's their problem, nothing wrong with the #'s.

If I where to skip a 25% water change and just do a 25% once that week.. opposed to someone who skips their 50% once a week. What do the numbers show then? Other then we're human and that does happen. Nitrates would build up to a more dangerous level.

don't skip water changes. what's your point?

if you skip 14 days of water changes on the 25% 2x a week schedule you'll end up with 70ppm on day 14 of not doing water changes.

if you skip 14 days of water changes on the 50% 1x a week schedule you'll end up with 60ppm on day 14 of not doing water changes.

60ppm<70ppm

On a purely numbers level your right, On a realistic application to husbandry practices. You're wrong. It's been proven by breeders and exotic fish keepers for years that you can never do to many water changes. Telling people 1x a week of 50% is fine... is Crap on toast.

This is why I sometimes hate science/labs/ect.

if this is what you took away from the information, you are truly confused!

the data doesn't say how many water changes you should make or how much water to change; it shows ONE thing: "1 large water change keeps your concentrations at a lower minimum (therefore lower average) than multiple smaller water changes adding up to the same volume over the same period of time."

btw 9/10 I'de wager the owners who do 2x a week or more water changes often do more then just a "weekly 50%" and often do more depending on the current state of the tank. It's not just the simple water change itself but the general maitenace that goes along with it, the over-all husbandry habits associated with it. which are a variable you won't find in a lab.

what the hell man!? we can't make people change their water!!! op's just showing how it can be done easier and more efficiently. what are you up in arms about?

The info is interesting.. but shoudln't be made in a blanketed statement to hobbyists in general. because it doesn't apply to the hobby 100%.

it should be and is a "blanket statement" in the respect that it's universal and mathematically proven. it applies to any and everyone.

whether you stick to your routine or not is an entirely different matter.

 

[MonsterMinis]

I use to do one large water change.. I don't now.. which is why I'm argueing so hard against what the "math" says.. because in RL it dosn't work. continueing to explaine the whys of it are apparently pointless being your completaly mis-understanding my points. Maybe 1 large WC a week or so might work for some tanks.. but with my species and set-ups not only is it impractical but dangerous. I am simply trying to warm peopel of the dangers in doing to few water changes.

Like I have pointed out multiple times already. The keepers of the most exotic and breeders of the most exotic species try and do daily WC or multiple a week. There are more then Nitrates in a tank to do damage to your fish. These peopel would not be successful if they didn't just get abit lucky but also take exceptional care of their fish.

Cleaning my horses stall once a week might save on bedding, but him walking around in his poop all week isn't better then cleaning it out every day. He'd probably get thrush in the very least or start developing upper respitory issues. Not to mention goodness knows what in eating his food in his own filth.

btw I am not a "Man".. and I'm not "up in arms" mearly offering my side of the issue.

My point is the OP is misinforming newbie out there. and of course it isn't our responsibility for others actions. But MFK always seems to try to offer the truth... not "preliminary scientific data". It's like telling us how wonderful this new Med is but it hasn't finished trials yet. It's interesting... But should everyone run out and start ordering it to switch their Meds? ( In the US peopel are good with this one. lol)

Thats really the only point to make. There is nothing WRONG with 2x25% weekly. and peopel have been preaching for years 50% weekly as a Minimum.... not the ideal.

like i said before te Math is easy and readily understood, or should be. But the practical application has yet to be seen. So Call me skeptical, because of my own personal history with water changes.

 

[dayak]

Its all good as long as u do do harms to the fish as for me I choose for larger wc with less frequent so in regard to this topic I do 50% weekly instead of 25% twice a week.
Its just like oil change some do every 3K some will do 15K it don't matter as long as they keep up with the the manufacturer reccomendetion and won't harm the engine, what's bad is when they do none

 

[ScatMan]

Assume both tanks start 20ppm, with 10ppm increase every 3.5 days. How long does it take for a fish in the tank with 25% wc twice a week expose to 40ppm? How long does it take for a fish with 50% wc weekly expose to 40ppm?

the 50% 1xpw will reach 40ppm about a week faster than 25% 2xpw.

it's much more important to note that the fish in the 25% 2xpw tank will spend the rest of their lives at a 5ppm higher average nitrate level than the fish in the 50% 1xpw tank.

were you trying to make a point or just asking the question? because vfc took the time to make and post charts that answered this question, it would be nice if you took the same time and courtesy to look them over.

 

[jcardona1]

So what about those running constant drip systems? What would the data look like for someone who dripped 10% a day, versus someone who did a 70% weekly water change? Same pattern?

 

[ScatMan]

I use to do one large water change.. I don't now.. which is why I'm argueing so hard against what the "math" says.. because in RL it dosn't work. continueing to explaine the whys of it are apparently pointless being your completaly mis-understanding my points. Maybe 1 large WC a week or so might work for some tanks.. but with my species and set-ups not only is it impractical but dangerous. I am simply trying to warm peopel of the dangers in doing to few water changes.

i'm not misunderstanding anything, you haven't made yourself clear as to why...

"1 large water change keeps your concentrations at a lower minimum (therefore lower average) than multiple smaller water changes adding up to the same volume over the same period of time."

"doesn't work".

nobody is advocating 1 large wc a week, it's simply being stated that; 1 large wc of 50% a week is better than 2 smaller water changes of 25% a week. or in other words...

"1 large water change keeps your concentrations at a lower minimum (therefore lower average) than multiple smaller water changes adding up to the same volume over the same period of time."

Like I have pointed out multiple times already. The keepers of the most exotic and breeders of the most exotic species try and do daily WC or multiple a week. There are more then Nitrates in a tank to do damage to your fish. These peopel would not be successful if they didn't just get abit lucky but also take exceptional care of their fish.

this doesn't disprove...

"1 large water change keeps your concentrations at a lower minimum (therefore lower average) than multiple smaller water changes adding up to the same volume over the same period of time."

Cleaning my horses stall once a week might save on bedding, but him walking around in his poop all week isn't better then cleaning it out every day. He'd probably get thrush in the very least or start developing upper respitory issues. Not to mention goodness knows what in eating his food in his own filth.

your comparison is dishonest.

if cleaning 50% of your horse's bedding 1x a week was enough to keep it happy and healthy, cleaning 25% 2x a week would be slightly worse for him because he would be standing around in slightly more poop on average.

that's a fair comparison.

what you're saying is that: 100% wc daily is better than 100% wc weekly, and that i agree with. but it doesn't compare to op's example. do you see how your analogy is completely different than what op is saying?

btw I am not a "Man".. and I'm not "up in arms" mearly offering my side of the issue.

i apologize miss, what exactly is your side of the issue?

My point is the OP is misinforming newbie out there.

that's an absolute lie and op proved it.

and of course it isn't our responsibility for others actions. But MFK always seems to try to offer the truth... not "preliminary scientific data". It's like telling us how wonderful this new Med is but it hasn't finished trials yet. It's interesting... But should everyone run out and start ordering it to switch their Meds? ( In the US peopel are good with this one. lol)

well if a medicine doesn't work, you have to prove why it's not to eliminate any possibility that it might be something other than the meds causing you a problem.

"the truth" is in the #'s.

Thats really the only point to make. There is nothing WRONG with 2x25% weekly. and peopel have been preaching for years 50% weekly as a Minimum.... not the ideal.

again, nobody is preaching how much or how often to change water, this is what you have repeatedly demonstrated that you don't understand. all op is saying is that...

"1 large water change keeps your concentrations at a lower minimum (therefore lower average) than multiple smaller water changes adding up to the same volume over the same period of time."

like i said before te Math is easy and readily understood, or should be. But the practical application has yet to be seen. So Call me skeptical, because of my own personal history with water changes.

you have never disproved the math in practice, so why are you skeptical?

 

[dayak]

So what about those running constant drip systems? What would the data look like for someone who dripped 10% a day, versus someone who did a 70% weekly water change? Same pattern?

If I have that sytem I would never do WC LOL
U changed 100% of water every 10 days hence 3 times of complete changed in a month of 30 days.
Unless over doing is ur thing and I don't have problem with that

 

[MonsterMinis]

your comparison is dishonest.

if cleaning 50% of your horse's bedding 1x a week was enough to keep it happy and healthy, cleaning 25% 2x a week would be slightly worse for him because he would be standing around in slightly more poop on average.

that's a fair comparison.


which is Wrong.... The horse would not get thrush because the filth would never get past a certain point... thats my point. The "average" doesn't matter only the "worst numbers"....

And calling me a liar for haveing over 20 yrs of animal husbandry experiance is nieve of you. The only thing the OP proved was 1 large water change dilutes NItrates better on a "average" basis then 2x25%... which has nothing to do with the actual husbandry of our animals since other reasons we do the water changes aren't addressed. So His data is incomplete. when it can be proved elevated nitrates won't do harm to our pets then You may call me ill-informed... BTW I was raised that calling someone a lier is hitting below the belt.

And my point is the "medacine" hasn't stood the test of time to be proven to work, and not do more damage.

The "truth" is better safe then sorry.

I am useing the OP's original numbers for comparison.. so as not to further confuse the debate. so when saying 50% is not better then 25%x2 I'm takeing into account the actual number differences being used. But useing the same numbers the OP threw out there as a grasping point.

keep the gloves up

 

[jcardona1]

If I have that sytem I would never do WC LOL
U changed 100% of water every 10 days hence 3 times of complete changed in a month of 30 days.
Unless over doing is ur thing and I don't have problem with that

There's no need to do a water change I had that on my 400g, never did a water change, and nitrates stayed at 10-15ppm. Drip systems with monster tanks is really the only way to go, and lots of people here use that very same system.

 

[MonsterMinis]

So what about those running constant drip systems? What would the data look like for someone who dripped 10% a day, versus someone who did a 70% weekly water change? Same pattern?

Not sure how the numbers crunch but I'm guessing your wasteing alot of water and should just do 1 big water change every now and then.. the "average" is better for your fish!