anyone feel like defending me? LOL

[beaslbob]

On the other board:

Water Changes-An Extension to Galloping Elephants - Reef Central Online Community

the poster refers to my galloping elephants I posted here

beaslbob's water change analysis

This is "my" water change analysis which with a given water change schedule, and a constant increase in parameter means the tank winds up at:


value before a water change=(parameter change between water changes)/(fraction of water change) + parameter in replacement water.

But then I can't post on rc so thought someone might like to help the conversation over there.

or not

:squigglemouth:

:wink:
:angel:

 

[beaslbob]

I never knew my galloping elephants were so well known.

 

[dictionaaron]

they got the formula all jacked up. i believe it is '
w=1-water change(20% wc makes this .8)
r= ppm increase per week
A0= starting value in ppm
n is the week
(A0+r)w^n + r(w^1+w^2+....+w^(n-1))

obviously if n=1 the whole right part drops off i just added w^1 and w^2 for example
seems to work out for me

 

[dictionaaron]

converting the infinite series you get htis

ppm after week n= (A0*w^n)+(rw(1-w^n)/(1-w))

 

[dictionaaron]

i don't have an rc account so someone else will have to fix them....or let them flounder

 

[Tomoko Schum]

I thought that you were a proponent of no water change.

Here's a great calculation and graphs on water changes by Dr. Randy Holms-Farley.

He concludes the article with the following statement:

"Water changes are a good way to help control certain
processes that serve to drive reef aquarium water away from its starting purity.
Some things build up in certain situations (organics, certain metals,
sodium, chloride, nitrate, phosphate, sulfate, etc.), and some things become depleted (calcium, magnesium, alkalinity, strontium, silica, etc.). Water changes can serve to help correct these
imbalances, and in some cases may be the best way to deal with them. Water
changes of 15-30% per month (whether carried out once a month, daily or
continuously) have been shown in the graphs above to be useful in moderating the
drift of these different seawater components from starting levels. For most reef
aquaria, I recommend such changes as good aquarium husbandry."

 

[beaslbob]

I thought that you were a proponent of no water change.

Here's a great calculation and graphs on water changes by Dr. Randy Holms-Farley.

He concludes the article with the following statement:

"Water changes are a good way to help control certain
processes that serve to drive reef aquarium water away from its starting purity.
Some things build up in certain situations (organics, certain metals,
sodium, chloride, nitrate, phosphate, sulfate, etc.), and some things become depleted (calcium, magnesium, alkalinity, strontium, silica, etc.). Water changes can serve to help correct these
imbalances, and in some cases may be the best way to deal with them. Water
changes of 15-30% per month (whether carried out once a month, daily or
continuously) have been shown in the graphs above to be useful in moderating the
drift of these different seawater components from starting levels. For most reef
aquaria, I recommend such changes as good aquarium husbandry."

I am

But more precisly is not relying on water changes to maintain things. Much better to have the system balanced out so water changes are not necessary.

As my forumla above shows it is more important to reduce the rate of change then use water changes. that is unless you do 100%/day water changes as in an open system for people that live near the sea.

my .02

 

[Tomoko Schum]

Water changes are necessary to reduce other nasty stuff, too, such as allelopathic chemicals that corals exude. Eric Borneman pointed that out a number of times.

Besides, how do you add some of those trace elements that are lost to organisms in your tank over time in a balanced manner?

 

[Young Frankenstein]

A more simple explanation would be appreciated, are you talking about water changes ?

 

[beaslbob]

A more simple explanation would be appreciated, are you talking about water changes ?

I was anyway.

The idea is how effective are water changes.

My assurtion is balancing out the tank is more effective and important.

but that's just my .02

 

[Tomoko Schum]

My assurtion is balancing out the tank is more effective and important.

What exactly are you trying to balance out in a tank?

 

[beaslbob]

What exactly are you trying to balance out in a tank?

anything and everything?