walkerbrody on other forum
Was asking what the effect of automating water changes to do 1g/day vrs ~20%per month.
Could someone please pass on these ideas.
What happens with water changes is that the just before water change values converge on:
just before water change values=values in replacement water+(rise in value between water changes)/(fraction of water changed)
for this example assume we are talking about a 1%/day change or a 20%/20 days change. (and assume you have some constant daily change in some parameter).
With 1%/day:
just before water change=(replacment water)+(daily change)*(1 day)/(1/100)=
_____________________=(replacement water)+100* daily change
with 20%/20 days:
just before water change=(replacement water)+(daily change)*(20 days)/(1/5)
_____________________=(replacement water)+(daily change)*20 days*5
_____________________=(replacement water)+100*daily change
the same exact values as the 1%/day
but the after water change value will:
%____before____after___buildup___nextbefore
1%___100________99_______1_______100
20%__100________80______20_______100
Of course (as most of you who know me expect me to say) the key to maintaining anything in the tank is to limit the daily change in conditions. When you acheive that then water changes have no effect and are unnecessary.
my .02
Was asking what the effect of automating water changes to do 1g/day vrs ~20%per month.
Could someone please pass on these ideas.
What happens with water changes is that the just before water change values converge on:
just before water change values=values in replacement water+(rise in value between water changes)/(fraction of water changed)
for this example assume we are talking about a 1%/day change or a 20%/20 days change. (and assume you have some constant daily change in some parameter).
With 1%/day:
just before water change=(replacment water)+(daily change)*(1 day)/(1/100)=
_____________________=(replacement water)+100* daily change
with 20%/20 days:
just before water change=(replacement water)+(daily change)*(20 days)/(1/5)
_____________________=(replacement water)+(daily change)*20 days*5
_____________________=(replacement water)+100*daily change
the same exact values as the 1%/day
but the after water change value will:
%____before____after___buildup___nextbefore
1%___100________99_______1_______100
20%__100________80______20_______100
Of course (as most of you who know me expect me to say) the key to maintaining anything in the tank is to limit the daily change in conditions. When you acheive that then water changes have no effect and are unnecessary.
my .02
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