the conlusion is on the #1 post of this thread by the OP, regarding this discussion.JTRG05;5159067; said:
Why a weekly 50% WC is better than two weekly 25% WCs
- Thread starter calioutlaw1a
- Start date
vfc;5159168; said:
Thank you, I find this very interesting. Could it be that in the first 40 days of nitrates appearing in a tank, say the end of a cycle in a new tank, it would be more effective to use the multiple 25% water change method opposed to the once 50% change? And then once the tank is established switch over to the 50% water change method once a week? This is assuming you are using fish for your cycle and not other methods, as nitrate levels without livestock would not matter.
Really? From your threadvfc;5158991; said:
If fish produce "x" amount of waste daily, which produces nitrate at daily rate of "y"vfc;5157648; said:
1st day, nitrate increases at (xy)
2nd day, nitrate increases at (x2y+xy) or (3xy)
3rd day, nitrate increases at (x3y+x2y+xy) or (6xy)
3.5th day, nitrate increases at (x3.5y+x2.5y+x1.5y+x0.5y) or (8xy)
4th day, nitrate increases at (x4y+x3y+x2y+xy) or (10xy)
5th day, nitrate increases at (x5y+x4y+x3y+x2y+xy) or (15xy)
6th day, nitrate increases at (x6y+x5y+x4y+x3y+x2y+xy) or (21xy)
7th day, nitrate increases at (x7y+x6y+x5y+x4y+x3y+x2y+xy) or (28xy)
With 50% wc weekly, at 7th day, nitrate level is at 28xy, and reduced to 14xy after wc.
With 25% wc twice a week, at 3.5th day, nitrate level is at 8xy, and reduced to 6xy after wc. At 7th day, nitrate level is 14xy, and reduced to 10.5xy after wc
The flaw from OP theory is he used constant rate for nitrate increment, and dismiss the important of waste removal from frequently wc.
jlnguyen74;5159551; said:
You have two major flaws in your thinking.
1 - Your calculations are based on a start up from 0 nitrates (same problem JTRG05 had on the previous page). Try picking up the calculation at day 40-50 where the nitrate levels have normalized.
2 - Solid waste does not break down into nitrate enough in 3.5 days to make that much of a difference. Most of the nitrate is coming from urine and long-term decay of solid matter (fish waste and dead driftwood/plants) trapped in the filter(s) for a few months.
BTW - I did laid-off one of those A-P guys; low productivity was the justification.
I kept wondering why my numbers didn't match up with your's vfc, I accounted for a "weekly" water change of 50%, ie 7 days, your data represents 6 days.
It appears that if 50% is changed every 6 days instead of 7 it is more effective than that of 25% water changes every 3 days (which mathematically makes sense).
Water changes of 25% every 3 days is more effective than that of 50% water changes every 7 however, which is what confused me. The one day did make a noticable difference, even at a normalized, later date.
I will admit however that on a small scale like that which nitrates are measured, the difference is not significant unless you are a terrible fish keeper with a HUGE amount of nitrates.
It appears that if 50% is changed every 6 days instead of 7 it is more effective than that of 25% water changes every 3 days (which mathematically makes sense).
Water changes of 25% every 3 days is more effective than that of 50% water changes every 7 however, which is what confused me. The one day did make a noticable difference, even at a normalized, later date.
I will admit however that on a small scale like that which nitrates are measured, the difference is not significant unless you are a terrible fish keeper with a HUGE amount of nitrates.
vfc;5159831; said:
What does this or your 45 years of keeping fish have anything to do? Are you so inscure that your theory is not so convincing, and put those in your post, to give it more credit?
Pick any number of ppm to start both tank with, 20ppm, for instance
With 50% wc weekly, at 7th day, nitrate level is at 20ppm+28xy, and reduced to 10ppm+14xy after wc.
With 25% wc twice a week, at 3.5th day, nitrate level is at 20ppm+8xy, and reduced to 15ppm+6xy after wc. At 7th day, nitrate level is 15ppm+14xy, and reduced to 11.5ppm+10.5xy after wc
Nitrate level in tank one is still higher in tank two at 7 days
jlnguyen74;5159551; said:
now i see why you are so confused you are talking about removing nitrate-producing-waste via water change. you do NOT remove nitrate-producing-waste with a water change, only vacuuming (or cleaning filters... etc....) will remove nitrate-producing-waste.
you're thinking of vacuuming (or cleaning filters... etc....) 2x a week + 25% water change 2x a week.
to keep it fair, you would also have to vacuum the other tank 2x a week and do 1 50% water change. -doing it this way, the 50% tank still has the advantage.
the only way you are right is by doing it your unfair way: vacuuming the the 25% tank 2x a week while only vacuuming the 50% tank 1x a week.
you are thinking and talking about something entirely different than the rest of us, it's no wonder why you don't understand.
if you don't understand this now, you are beyond any hope of help... but i will do my best damn it!
What do you do when you doing water change? You just take out water, without vaccuuming? And how can someone vacuum a tank twice a week when he only do 1x weekly water change?ScatMan;5160566; said:
you are talking about removing nitrate-producing-waste via water change. you do NOT remove nitrate-producing-waste with a water change, only vacuuming (or cleaning filters... etc....) will remove nitrate-producing-waste.
you're thinking of vacuuming (or cleaning filters... etc....) 2x a week + 25% water change 2x a week.
to keep it fair, you would also have to vacuum the other tank 2x a week and do 1 50% water change. -doing it this way, the 50% tank still has the advantage.
the only way you are right is by doing it your unfair way: vacuuming the the 25% tank 2x a week while only vacuuming the 50% tank 1x a week.
you are thinking and talking about something entirely different than the rest of us, it's no wonder why you don't understand.
if you don't understand this now, you are beyond any hope of help... but i will do my best damn it!
