Small water changes after cycle completes?

[Blukraken]

My cycle completed and need to do a wc to remove excess nitrates. I don't have the capacity at the moment to do a large water change all at once on my 40B+20g sump. I only have a couple 5 gallon buckets. I took out roughly 50% for a wc and realized it was getting late while each bucket takes a little less than an hour to fill (still 4 more 5 gallon buckets to go). Will the bacteria on the rocks be fine if they start to dry out or am I screwed? I would assume multiple 10% water changes over the course of a day will equal out to 50% right?

 

[HankstankXXL750 Verified Sponsor]

I think you will be ok if they start to dry out, but I wouldn’t leave them too long.

As far as 10% changes from starting nitrates

1st = 90% left
2nd = 81% left
3rd = 72.9% left
4th = 65.51% left
And so on only reducing amount by 10% of remaining every time.
And that doesn’t account for any new production.
Need to get it filled back up, but might want to by a larger brute trash can and prep water so you can change out close to 100% so you start really low.

 

[Jekyl]

Get yourself a 32g brute trash can to hold your RODI while filling and for mixing the saltwater.

 

[Blukraken]

That's the idea. Do I need a large powerhead to circulate the water in the brute or will a small one work?

 

[HankstankXXL750 Verified Sponsor]

That's the idea. Do I need a large powerhead to circulate the water in the brute or will a small one work?

I use a minimum 500 gph quiet one. The larger the better as it dissolves the salt better. Using a smaller one could be frustrating and make you feel that it is a bad plan. However a smaller pump and or large air stone can work. You will need to move the pump around so it stirs all the salt.

 

[MTLAndy]

My cycle completed and need to do a wc to remove excess nitrates. I don't have the capacity at the moment to do a large water change all at once on my 40B+20g sump. I only have a couple 5 gallon buckets. I took out roughly 50% for a wc and realized it was getting late while each bucket takes a little less than an hour to fill (still 4 more 5 gallon buckets to go). Will the bacteria on the rocks be fine if they start to dry out or am I screwed? I would assume multiple 10% water changes over the course of a day will equal out to 50% right?

Not sure about the answer; but doing 1 x 50% WC (vs) 5 x 10% WC, is not the same end result (in terms of how much old water was changed.

If you do 5x 10%, the first change removes 10% of old water; the second removes 9%, 3rd 8.1%, 4th 7.3%, and 5th 6.6% of the old water... for a total of about 40% WC. My math might be off, but the logic should be right... because each time you do a WC; you are removing some of the new water too.