1 big water change better than 2 smaller one??

[jackalcleo]

Hi,

For many years was wondering on this question

If my main aims is to greatly reduce nitrate is 1 time 50% change better than 2 X 25% change?

The 2 times means remove 25% add in new 25% then the next day or few days later do the same again.

This is so as to change 50% really need a lot of storage tub or big one.

Please share your views?

Thanks.

[Xtraster]

IMO, If nutrient export is your main concern, 50% water change will be better than doing 25% twice over a few days.

It also depend on your resources available (effort, time, etc) as there is no hard and fast rule I feel. So long it is a routine you follow, the tank species will adapt accordingly over time.

Hope to hear more views too on this topic as i read some tanks don't do water change at all.

[kenyee]

Yes 50% wc one time will b more effective in having cleaner water..there is really no fixed set of rules that guarantee success in reefing..if bioload is low, think can no need wc ba..cheers n happy reefing

[jackalcleo]

14 hours ago, kenyee said:

Yes 50% wc one time will b more effective in having cleaner water..there is really no fixed set of rules that guarantee success in reefing..if bioload is low, think can no need wc ba..cheers n happy reefing

Thanks for clearing my doubts. Wonder now how to do 50% change ( more than 300l) 

[kenyee]

5 minutes ago, jackalcleo said:

Thanks for clearing my doubts. Wonder now how to do 50% change ( more than 300l) 

Get more pails..one pail ard 20-25L..u need more pails?

[jackalcleo]

Kidding me 

[jackalcleo]

Think probably dose vinegar will be easier

[sherman]

Carbon dosing confirm can reduce NO3 level.

I am doing it.

[kenyee]

3 hours ago, jackalcleo said:

Kidding me 

Bro, u mean using pails is a joke?haha

[pcw]

Suppose you change 50% of your water at once, this would mean (theoretically) that you're removing 50% of nitrates.

On the contrary, if you change 25% first, this would mean that you're removing 25% of nitrates (so 75% of the original level of nitrates is left). Then you'll have to top up with new salt water. Thereafter, removing 25% again on another day would mean that you're removing (in theory) 25% of the 75% of the original level of nitrates, about 18.75% of the original level of nitrates. So in total, you'll only be removing 25% + 18.75% of the nitrates instead.

[JMW]

How much nitrates are you starting with?

As pcw mentioned, choosing between one or two changes, it's a question of whether you are reducing 50% or 44% of nitrates, which in absolute terms could be either a few ppm or decimal points of a ppm. In that context, I'd do 2 changes of 25% to reduce the shock on the livestock.. hope this helps!

[jackalcleo]

At the moment not able to reduce nitrate level below 50mg/L even with bio pellet / weekly 25% water change / oversize skimmer.

Probably hitting the limit for the numbers of livestock  (19 fishes and some pretty big ones).

Still looking for a few more and probably stop at 25 fishes. 

[jackalcleo]

7 hours ago, sherman said:

Carbon dosing confirm can reduce NO3 level.

I am doing it.

Using vinegar or vodka? How much dosage you sue per day and for what size tank?

Read up that it have some side effects and so do not wish to overdo it?

If below 20mg/l I'm more than happy

[sherman]

What is yr tank volume? There is a calculate u can download.
Search for DSR calculator

Sent from my LG-H990 using Tapatalk

[alons]

_{50% water change will stress your live stock, i would not do this unless there is an emergency, and for sure reduce nitrate level in a FOWLR tank does not qualify.}

Weekly changes of 10-15% for 2-3 times will do the trick, add biopalets, better strategy from experience.