Help with water changes

[Chucky]

So I’ve often always wondered this next question so here we go, do you calculate your water changes by the total water volume in the tank/sump or do you calculate it by the total gallons of the tank? I have a Biocube 32g and with rocks/ sand it holds roughly 23 gallons of total water volume. Whenever I do water changes I just change 3 gallons at a time once a week, am I doing this correctly?

 

[Mr. Mojo Rising]

you're overthinking it.
Sometimes I change 5% sometimes I change 35%
No need to calculate water volume minus rock volume, keep it simple as possible.

 

[Fishology]

So I have a 40 close enough to size I would change about five gallon of water for a 32 and mix the sand up a bit to get waste out of the sand

 

[Chucky]

So I have a 40 close enough to size I would change about five gallon of water for a 32 and mix the sand up a bit to get waste out of the sand

You’d recommend 5g per water change? I can see why you would wanna change more because when I do the 3 gallon change I sometimes don’t have enough time to get all the debris off the entire sand bed

 

[X-37B]

I just keep it simple. If my tank is say 100g's then 10% is 10g's. I have always gone off tanks suggested volume. Easy and it works.

 

[MoshJosh]

I usually change based on the size of bucket I have or just choose some arbitrary amount. . . though I do aim for 25-30% of total water volume. (oh and I calculate "total volume" based on tank size + sump size, so 15 gallon tank plus 5 gallon sump is 20 gallons, regardless of rock, sand, etc. . .)

recently I am changing about 4 gallons a week. . . only because any more and my highest corals would be out of the water (I know they would be fine, but want to minimize any stress).

 

[Fishology]

You’d recommend 5g per water change? I can see why you would wanna change more because when I do the 3 gallon change I sometimes don’t have enough time to get all the debris off the entire sand bed

Ya when you do five you can clean the glass and suck up the algae and remove all algae or most form the sand

 

[Chucky]

I just keep it simple. If my tank is say 100g's then 10% is 10g's. I have always gone off tanks suggested volume. Easy and it works.

Ya when you do five you can clean the glass and suck up the algae and remove all algae or most form the sand

That makes more sense to me, I guess I get to technicall at times

 

[Fishology]

That makes more sense to me, I guess I get to technicall at times

Hey we all have stuff you Learn it just take time

 

[Chucky]

Hey we all have stuff you Learn it just take time

Never to old to learn new tricks or hacks

 

[EricR]

I agree with everyone that you don't really need to overthink it but, to answer your original "curiosity" question:

If you change 3 gallons and your total system water volume is 23 gallons, even though tank is 32 gallon,
I'd call that a 13% water change (3/23)

 

[Kongar]

Yup definitely overthinking it. It's not about exactly how much water you change, it's about keeping your nutrients down and replenishing trace elements. In a 32G, you can ditch all the fancy equipment and just rely on water changes (because it's easy to mix up that small amount of water). 10% a week (whether it's 10% of 32, or 10% of 23) is probably too LITTLE water to do other things like clean your sand. I have a 20G tank volume, and I mix up 2 five gallon buckets every other week. I do 4 gallons in each bucket because it's easier to pour into the tank. So 8 gallons every other week. That gives me enough water to suck up crap with the siphon, and it keeps my nitrates at about 2ppm. There's a bit more swing in the nutrients doing it every other week, but not enough where it affects anything.

My vote would be do what I do. 8 gallons every other week, and measure your nitrates/phosphates. Are they climbing? Add another 4 gallons. Are they dropping too low? Do less or do it every third week. It's about your water parameters, nothing more. The easier you make things on yourself, the more likely you'll be to DO water changes and maintain the tank in the first place.

 

[X-37B]

Yup definitely overthinking it. It's not about exactly how much water you change, it's about keeping your nutrients down and replenishing trace elements. In a 32G, you can ditch all the fancy equipment and just rely on water changes (because it's easy to mix up that small amount of water). 10% a week (whether it's 10% of 32, or 10% of 23) is probably too LITTLE water to do other things like clean your sand. I have a 20G tank volume, and I mix up 2 five gallon buckets every other week. I do 4 gallons in each bucket because it's easier to pour into the tank. So 8 gallons every other week. That gives me enough water to suck up crap with the siphon, and it keeps my nitrates at about 2ppm. There's a bit more swing in the nutrients doing it every other week, but not enough where it affects anything.

My vote would be do what I do. 8 gallons every other week, and measure your nitrates/phosphates. Are they climbing? Add another 4 gallons. Are they dropping too low? Do less or do it every third week. It's about your water parameters, nothing more. The easier you make things on yourself, the more likely you'll be to DO water changes and maintain the tank in the first place.

Lots of ways to be successfull so pick one and stay with it.
In my 20g nano I do 2g's every month.
I currently dose 12ml of esv 2x a day. I dose 1ml of ez trace.
My system would never be stable with WC's alone but thats my system and each one is different.

 

[Chucky]

Lots of ways to be successfull so pick one and stay with it.
In my 20g nano I do 2g's every month.
I currently dose 12ml of esv 2x a day. I dose 1ml of ez trace.
My system would never be stable with WC's alone but thats my system and each one is different.

Beautiful setup!! Thanks for your input/advice