Go Back   Aquarium Advice - Aquarium Forum Community > Saltwater and Reef > Saltwater Reef Aquaria
Click Here to Login

Join Aquarium Advice Today
Reply
 
Thread Tools Search this Thread Display Modes
Please support our sponsors and let them know you heard about them on AquariumAdvice.com
 
Old 12-12-2013, 11:32 AM   #11
SW REEF 18+ YEARS
Community Admin
 
melosu58's Avatar



Tank of the Month Award
 
Join Date: Oct 2004
Location: Virginia
Posts: 38,244
Im glad you are doing PWC`s. As mentioned above you should not have to dose iodine as its in your SW mix. Never dose anything you are not testing for.
__________________

__________________

SITE ADMINISTRATOR

You can view many of my fish and corals in my photo albums in my profile.

View my tank


AA Community Rules|AA TOS

Forums 101 - posting, accounts, basics
melosu58 is offline   Reply With Quote
Old 12-12-2013, 12:59 PM   #12
Aquarium Advice Addict
 
mr_X's Avatar


 
Join Date: Apr 2008
Location: Fairless Hills, Pa.
Posts: 17,895
Send a message via MSN to mr_X
Quote:
Originally Posted by MarinaClown View Post
Edit: to sound nicer
What you are saying is doing a 10% weekly water change is the same as doing 10% monthly. We shouldn't ignore the fact that more water volume goes in per month doing weekly water changes.
What I'm saying? I'm saying exactly what I said above. You asked for an explanation of the dilution. I have no idea what percentages are, nor do I even care.
__________________

__________________
thanks,
Doug
mr_X is offline   Reply With Quote
Old 12-12-2013, 01:22 PM   #13
Aquarium Advice Addict
 
TheTodd's Avatar
 
Join Date: May 2012
Location: Palm Springs, CA
Posts: 3,110
Exactly right. 10% a week is nowhere near 40% a month, as you are going to be getting some newer and some older water. With a single 40% change, you are taking out 40% old and putting in 40% new.

IMO, the Bottom line is that water changes are important, as they both replenish nutrients and extract nitrates. The exact percentage does not matter, as long as everything is healthy and levels stay in check. My 240g with one, ten or twenty fish is going need adjusted changes as the stock increases.
__________________
TheTodd is offline   Reply With Quote
Old 12-12-2013, 02:04 PM   #14
Aquarium Advice FINatic
 
MarinaClown's Avatar
 
Join Date: Jan 2013
Location: Marina Del Rey, CA
Posts: 790
I am actually indifferent to what percentage it is also.

To Mr. X: I questioned another poster's reply that provided no basis whatsoever for his or her claim. Your reply started with the word Because which led me to understand that you were trying to explain the same exact point I was questioning.
To The Todd: I also don't quiet understand a claim that states "10% a week is nowhere near 40% a month" without any explanation which in my view could only be mathematical as well as chemical to some degree. I understand you said "some newer and older water" in your reference to dilution. But as a mathematically challenged person I don't find it persuasive. Sorry.
I don't really have a problem with either one of you personally as both of you have contributed to my earlier threads in a positive way. I just wish there were more data in your answers to support your claims.
I can explain my statement by the following reasoning which is by no means perfect mathematically as dilution is definitely an important part of the process. When I do a 10% water change on 10 gallons, I am putting 4 gallons of new water per month which constitutes a 40% change.
But like TheTodd said "water changes are important, as they both replenish nutrients and extract nitrates."
__________________
MarinaClown is offline   Reply With Quote
Old 12-12-2013, 03:27 PM   #15
Aquarium Advice Addict
 
molliwopp's Avatar
 
Join Date: Nov 2012
Location: Uk, England.
Posts: 2,110
Let me have ago at explaining it. Im using easier numbers to make it simpler to understand but the underlying princible is still there.

Example:
Ok so lets say you do a 10% change daily. And i do 70% weekly. 10% × 7days = 70% right? or so you thought.

Lets say both tanks have equal amounts of nitrates of 100ppm and lets say our fishes produce 5ppm of nitrate daily.

Your first change 1.) : 10% of 100ppm is 10ppm so now you have 90ppm +5 (fish production) 95ppm.

2.) 10% of 95ppm is 9.5ppm, 95 - 9.5 = 85.5 +5 =90.5ppm
3.) 10% of 90.5 = 9.05, 90.5 - 9.05 = 81.45 +5 = 86.45
4.) 10% of 86.45 = 8.645, 86.45 - 8.645= 77.805 + 5 = 82.805.
5.) 10% of 82.805 = 8.2805, 82.805 - 8.2805 = 74.5245 +5 = 79.5245
6.) 10% of 79.5245 = 7.95245, 79.5245 - 7.95245 = 71.57205 + 5 = 76.57205
7.) 10% of 76.57205 = 7.657205, 76.57205 - 7.657205 = 68.914845 +5 = 73.914845.

Right now for my 70% 100ppm + 6days worth with 5ppm added to the total on day 7. Exactly like i did at the end of day 7 with yours. production is 30ppm +100 = 130ppm, 70% of 130 = 91ppm removed leaving 30% old water containing the other 39ppm + the day 7. 5ppm = 44ppm

73.9ppm vs 44ppm
30ppm more left over after doing 10% daily compared to the large single change.

It will be less dramatic with one 40% vs 4 10% I chose the numbers carefully to stop them becoming to big to type and an even bigger mess to read.
__________________
Fish die belly upward and rise to the surface. It's their way of falling.


[SIGPIC][/SIGPIC]
molliwopp is offline   Reply With Quote
Old 12-12-2013, 03:29 PM   #16
Aquarium Advice Addict
 
TheTodd's Avatar
 
Join Date: May 2012
Location: Palm Springs, CA
Posts: 3,110
I probably can not explain it properly in mathematical terms. I do know that four 10% does not equal a net 40% change. It just can't.

If you have a 100 gallon tank and change 10 gallons today, you have done 10%. If a week from today, you do another 10 gallons, that is 10%, but some of the water you took out was some of the new that you added last week, so maybe its more like 8% net (who knows?). Continue losing 2% for weeks 3 and 4 and you are probably closer to a net monthly change of 33-35%. That is not taking into account that smaller changes do less to bring things like nitrates down. I'm a bigger fan of doing changes as needed and I typically do 30-40% at once. If my nitrates get high after three weeks, i do a change. If they stay low for 6 weeks, then I will change when they creep up. I am talking for FOWLR, so for reef, the nutrient replacement probably needs to occur more on a schedule.
__________________
TheTodd is offline   Reply With Quote
Old 12-12-2013, 05:52 PM   #17
Aquarium Advice Addict
 
Mebbid's Avatar



POTM Champion
 
Join Date: Mar 2013
Location: Michigan USA
Posts: 12,569
Wow guys... This is really just arguing semantics and is kind of ridiculous.
__________________
"The simplest explanation for some phenomenon is more likely to be accurate than more complicated explanations." -Occam's razor
Mebbid is offline   Reply With Quote
Old 12-12-2013, 06:14 PM   #18
Aquarium Advice Freak
 
pritchard's Avatar
 
Join Date: Apr 2011
Posts: 241
All I'm saying is 10% weekly works wonders for me ! Lol
__________________
pritchard is offline   Reply With Quote
Old 12-12-2013, 06:16 PM   #19
Aquarium Advice Freak
 
pritchard's Avatar
 
Join Date: Apr 2011
Posts: 241
The way I see it is just weekly replenishment of trace elements !
__________________
pritchard is offline   Reply With Quote
Old 12-21-2013, 05:59 AM   #20
Aquarium Advice Apprentice
 
LKemp712's Avatar
 
Join Date: Dec 2013
Location: Bismarck,ND
Posts: 42
Dosing iodine? What levels? I just started a coral tank and was contemplating calcium and magnesium to start.
__________________

__________________
LKemp712 is offline   Reply With Quote
Reply

Please support our sponsors and let them know you heard about them on AquariumAdvice.com

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off








» Photo Contest Winners








Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -4. The time now is 09:40 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.