Why a weekly 50% WC is better than two weekly 25% WCs

[krichardson]

What do you do when you doing water change? You just take out water, without vaccuuming?

I thought that that was the only way to do a water change.

 

[vfc]

......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

You are assuming all the solid waste will completely turn into nitrates in 3.5 days; in fact you assume solid waste will suddenly turn into nitrates in 1 day.. Do you have any scientific data to support your assumption? The solid waste I vacuum each week is still the same shape it was all week.

 

[vfc]

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)....

Like I mentioned before, my excel model can't handle half days because of the way I detect the WC day (MOD function with no remainder). So I went with 3 & 6. 4 & 8 days has the same result.

 

[Freezekougra]

The reason why I choose one weekly 50% w/c over two 25% w/cs is simply because I don't like doing two water changes a week...not because I believe one is better than the other.

 

[ScatMan]

What do you do when you doing water change? You just take out water, without vaccuuming?

that's exactly right, i don't have gravel, therefore i never vacuum.

but most people with gravel don't vacuum every time they do a water change. it's too much of a pain in the ass to remove all the decorations, vacuum the gravel , replace the decorations, and smooth the gravel 2x a week.

do you vacuum your tanks 2x a week? sounds like a lot of unnecessarily wasted effort to me.

And how can someone vacuum a tank twice a week when he only do 1x weekly water change?

and some people hook their vacuum up to a canister.




you need to think first before you go about posting up whatever nonsense you can grasp at trying to save face because you were wrong this whole exhaustive conversation.

just because you don't know the answer to something, doesn't mean that there is no answer. and these stupid emoticons you keep using just makes you look like you have nothing really to say. your only defense is ""..... you don't even deserve my help if you're just going to play rude games like this.

 

[jlnguyen74]

that's exactly right, i don't have gravel, therefore i never vacuum.

but most people with gravel don't vacuum every time they do a water change. it's too much of a pain in the ass to remove all the decorations, vacuum the gravel , replace the decorations, and smooth the gravel 2x a week.

do you vacuum your tanks 2x a week? sounds like a lot of unnecessarily wasted effort to me.

You're right. I shouldn't use the word vacuum. I should say remove nitrate-producing-waste, or just waste. Whether tank has gravel or not, when syphoning water out for doing wc, doesn't anyone also syphon out waste in the tank?

 

[jlnguyen74]

You are assuming all the solid waste will completely turn into nitrates in 3.5 days; in fact you assume solid waste will suddenly turn into nitrates in 1 day.. Do you have any scientific data to support your assumption? The solid waste I vacuum each week is still the same shape it was all week.

I didn't assume all the solid waste will completely turn into nitrate, or have data to support. That's why variable "x" was chosen. It's an unknown factor, but it's there.

 

[vfc]

I didn't assume all the solid waste will completely turn into nitrate, or have data to support. That's why variable "x" was chosen. It's an unknown factor, but it's there.

Since the waste in my tanks (highly visible with large fish and black sand) doesn't change in one week(let alone 3.5 days); the variable x is ~0 nitrates. So the conclusion is 50% weekly WCs are better than 25% twice a week.

 

[ScatMan]

I thought that that was the only way to do a water change.

apparently you never heard of a drip-system or bare-bottom?

 

[ScatMan]

^^^ sorry man, i thought you were saying that vacuuming was the only way you knew to do a water change.

forgive me, i've been on the defensive for too long, lol!