Canreef Aquatics Bulletin Board  

Go Back   Canreef Aquatics Bulletin Board > General > Reef

Reply
 
Thread Tools Display Modes
  #1  
Old 11-28-2014, 04:06 PM
reefwars reefwars is offline
R.I.P.
 
Join Date: Apr 2010
Location: Calgary, AB
Posts: 6,186
reefwars will become famous soon enough
Default

Quote:
Originally Posted by Masonjames View Post
But when these two identical percentages are changed over a bi weekly, monthly, etc. period of time the difference of both removal and additions is very very small. A few percent, to points of a percent. So one could argue this is less effective, but the difference is literally so small that it's nearly irrelevant.


exactly
__________________
........
Reply With Quote
  #2  
Old 11-28-2014, 04:22 PM
Reef Pilot's Avatar
Reef Pilot Reef Pilot is offline
Member
 
Join Date: Nov 2010
Location: Langley BC
Posts: 1,883
Reef Pilot is on a distinguished road
Default

Quote:
Originally Posted by reefwars View Post
exactly
Gawd,... I have better things to do,... but here goes one more time.

Start with a barrel of 100 apples. Change 10% volume (incl that percentage of oranges from the previous day) every day for 10 days with oranges. (Of course, after a day you will have to start slicing the oranges and apples a bit to get the right proportions...)

At the end of 10 days, in the barrel, you will still have 34.86784401 apples and only 65.132156 oranges. Oranges can represent new water, and apples the old water nutrients.

And if you change 100% of the apples with the oranges in one change, you would have all oranges and no apples.

And daily changes over a longer period of time, just makes it worse... Not sure how else to explain it. If this doesn't do it, I give up...
__________________
Reef Pilot's Undersea Oasis: http://www.canreef.com/vbulletin/sho...d.php?t=102101
Frags FS: http://www.canreef.com/vbulletin/sho...d.php?t=115022
Solutions are easy. The real difficulty lies in discovering the problem.
Reply With Quote
  #3  
Old 11-28-2014, 04:55 PM
Masonjames Masonjames is offline
Member
 
Join Date: Jun 2013
Location: Lethbridge
Posts: 105
Masonjames is on a distinguished road
Default

Quote:
Originally Posted by Reef Pilot View Post
Gawd,... I have better things to do,... but here goes one more time.

Start with a barrel of 100 apples. Change 10% volume (incl that percentage of oranges from the previous day) every day for 10 days with oranges. (Of course, after a day you will have to start slicing the oranges and apples a bit to get the right proportions...)

At the end of 10 days, in the barrel, you will still have 34.86784401 apples and only 65.132156 oranges. Oranges can represent new water, and apples the old water nutrients.

And if you change 100% of the apples with the oranges in one change, you would have all oranges and no apples.



And daily changes over a longer period of time, just makes it worse... Not sure how else to explain it. If this doesn't do it, I give up...
Quote:
Originally Posted by Reef Pilot View Post
.

Think of it another way, and maybe might make more sense to you. If you exchange 10% of your water each day over 10 days, you will have changed 100% of your volume. But you still have some of your original water and nutrients present because of your daily mixing and dilution. However, if you change 100% of your water in 10 days, for sure you will have a complete exchange of nutrients and no old water.
Those exact same principles of mixing and dilution apply to any percent changed so I don't understand the differnce your trying make. With your apple to oranges comparison, you are neglecting to apply the very principles you brought up originally. You are applying the rule that you are removing 100% of whatever percent of apple you are removing. But you've neglected to apply your mixing and dilution rule that once In the barrel, those apples and oranges must become so thoughly mixed they become for the most part unrecognizable from each other. Now pull out a handful and calculate from the slurry how many apples and how many oranges.
If you change x% volume biweekly with a single water change, you will have changed x% of your systems volume monthly. But you still have some of your original water and nutrients present because of mixing and dilution. If you change x% volume daily you will have change x% volume of your systems volume monthly. But you still have some of your original water and nutrients present because of mixing and dilution. Unless your doing a single 100% change, your still leaving behind old water and nutrients and removing a percentage of the previous change. I guess one could consider 2 week old water changed already spoiled removing the potential to remove a percent of brand spanking new water by changing daily. But those principles of mixing and dilution are actually what sorta makes the math work on a small scale change as the mixing and dilution happeneds over a much larger body.
Reply With Quote
  #4  
Old 11-28-2014, 05:13 PM
Reef Pilot's Avatar
Reef Pilot Reef Pilot is offline
Member
 
Join Date: Nov 2010
Location: Langley BC
Posts: 1,883
Reef Pilot is on a distinguished road
Default

Don't know what else to say.... Do the math for yourself and you will see. You can use any example or proportion you want. The point is the same. And that is that changing the same vol of water less frequently gives you a bigger bang for the buck with nutrient exchange.

I am not arguing that frequent water changes are bad. It's just that you need to do bigger volumes to make up the difference over time. In fact, if your tank has high nutrients, a big water change is not as good because of the possible rapid composition change of your parameters. But that is another issue... My point above is just about the math...
__________________
Reef Pilot's Undersea Oasis: http://www.canreef.com/vbulletin/sho...d.php?t=102101
Frags FS: http://www.canreef.com/vbulletin/sho...d.php?t=115022
Solutions are easy. The real difficulty lies in discovering the problem.
Reply With Quote
  #5  
Old 11-28-2014, 05:20 PM
reefwars reefwars is offline
R.I.P.
 
Join Date: Apr 2010
Location: Calgary, AB
Posts: 6,186
reefwars will become famous soon enough
Default

RHF:

"Previous articles on water changes have "shown" that small water changes are not useful, and have sometimes left the impression that even many small water changes are not beneficial. It is also "common knowledge" among many reef aquarists that continuous water changes (where water is added and removed at the same time, usually by automatic pumping) is not very useful "because this removes some of the new water that was just added." As I'll show, these assumptions do not stand up to analysis for typical water change scenarios. Consequently, whether choosing to change a lot of water, or only a little, and whether it is done continually, daily, or only rarely, more water change options are available to aquarists than many realize. These increased options' availability may permit busy aquarists to spend time on other important activities, and less time on water changes, while still accomplishing the same goals."



haha well if all the same to you folks ill take my advice from scientists as i usually do as they have put the actual research into it and done the math using the variables and not ignoring them , especially the ones that have debunked many aquarium myths.....like apples and oranges
__________________
........
Reply With Quote
  #6  
Old 11-28-2014, 05:33 PM
Reef Pilot's Avatar
Reef Pilot Reef Pilot is offline
Member
 
Join Date: Nov 2010
Location: Langley BC
Posts: 1,883
Reef Pilot is on a distinguished road
Default

Quote:
Originally Posted by reefwars View Post
RHF:

"Previous articles on water changes have "shown" that small water changes are not useful, and have sometimes left the impression that even many small water changes are not beneficial. It is also "common knowledge" among many reef aquarists that continuous water changes (where water is added and removed at the same time, usually by automatic pumping) is not very useful "because this removes some of the new water that was just added." As I'll show, these assumptions do not stand up to analysis for typical water change scenarios. Consequently, whether choosing to change a lot of water, or only a little, and whether it is done continually, daily, or only rarely, more water change options are available to aquarists than many realize. These increased options' availability may permit busy aquarists to spend time on other important activities, and less time on water changes, while still accomplishing the same goals."



haha well if all the same to you folks ill take my advice from scientists as i usually do as they have put the actual research into it and done the math using the variables and not ignoring them , especially the ones that have debunked many aquarium myths.....like apples and oranges
Are you trying to rationalize your incorrect math?
Like I said before, I am not arguing the merits of frequent vs infrequent water changes (although I do question small daily changes). My point is about the math, which even RHF above acknowledges.
It's good to quote articles, but it is also important to understand what they are saying, too.
__________________
Reef Pilot's Undersea Oasis: http://www.canreef.com/vbulletin/sho...d.php?t=102101
Frags FS: http://www.canreef.com/vbulletin/sho...d.php?t=115022
Solutions are easy. The real difficulty lies in discovering the problem.

Last edited by Reef Pilot; 11-28-2014 at 05:40 PM.
Reply With Quote
  #7  
Old 11-28-2014, 05:41 PM
denny_C denny_C is offline
Banned
 
Join Date: Nov 2013
Location: calgary,ne
Posts: 466
denny_C is on a distinguished road
Default

Quote:
Originally Posted by Reef Pilot View Post
My point is about the math, which even RHF above acknowledges.
yes but the math is a very small difference when applied permanently , if you read the article you'll see in the graphs how small the differences actually were ....very small.......randy also clearly states that the amount is so small that its irrelevant while the risks are many and not so irrelevant


not sure whats so hard to understand......seems the rest of the experienced reef world gets it so not sure what you question about smaller water changes lol

are you saying that small water changes arn't adequate enough of a practice?

why would you think a larger water change that not only removes but changes the system overall the more the larger it gets is any better than a small one?
Reply With Quote
  #8  
Old 11-28-2014, 05:52 PM
Masonjames Masonjames is offline
Member
 
Join Date: Jun 2013
Location: Lethbridge
Posts: 105
Masonjames is on a distinguished road
Default

What Denny? You mean to tell me you have never done the research yourself? That's it, from now on I don't believe a thing you say... Ha ha ha ; )

I gotta agree with RHF ( and not Denny for his lack of research) as well. The only problem with the apple and oranges math, is that it is only considering the values your choosing to acknowledge while deliberately choosing to ignore others.

But tomatoes tomatos. Apples to oranges. As long as buddy is doing water changes then we all can be happy.

Sorry if we got a bit off topic op. Not much value in all that considering the context of your original post.
Reply With Quote
  #9  
Old 11-30-2014, 06:29 AM
Kellyscoral Kellyscoral is offline
Member
 
Join Date: May 2014
Location: Calgary
Posts: 43
Kellyscoral is on a distinguished road
Default

Hmmm - I may have had one too many tequila shots cause this is all clear as mud in my brain!!
Reply With Quote
  #10  
Old 11-30-2014, 02:38 PM
Masonjames Masonjames is offline
Member
 
Join Date: Jun 2013
Location: Lethbridge
Posts: 105
Masonjames is on a distinguished road
Default

Quote:
Originally Posted by Kellyscoral View Post
Hmmm - I may have had one too many tequila shots cause this is all clear as mud in my brain!!
Lol. Is this lasts night tequila or this mornings were talking about? Jks.

What needs clarifying? My point is simply this. Decide on the type of critters you wish to keep. Determine the enviromnet where they come from. And build your system around there needs. Some tools (like algae) can aid in creating an enviroment better suited to there needs, and some tools (like algae) can give you a leg down in creating an enviroment better suited to there needs.
Reply With Quote
Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT. The time now is 12:59 AM.


Powered by vBulletin® Version 3.7.3
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.