Element X requires what % of water change to be replenish??

[Reefahholic]

Element X = 100 ppm

Your system is growing rapidly and consuming 10 ppm of Element X each week. We have already tested our salt-mix and confirmed that Element X is present in the salt. We found the concentration at 100 ppm. Element X was initially at 400 ppm, but now has dropped to 390 ppm. You rely solely upon water changes for supplementation of all elements.

What % of water needs to be changed to replenish Element X back to 100% or 400 ppm?

@rtparty
@Hans-Werner
@Randy Holmes-Farley
@MnFish1

 

[blaxsun]

How often do you perform water changes?

 

[Reefahholic]

Once a week.

I don’t do any, but let’s say Joe reefer does 10% weekly or 20% biweekly.

 

[Garf]

Element X = 100 ppm

Your system is growing rapidly and consuming 10 ppm of Element X each week. We have already tested our salt-mix and confirmed that Element X is present in the salt. We found the concentration at 100 ppm. Element X was initially at 400 ppm, but now has dropped to 390 ppm. You rely solely upon water changes for supplementation of all elements.

What % of water needs to be changed to replenish Element X back to 100% or 400 ppm?

@rtparty
@Hans-Werner
@Randy Holmes-Farley
@MnFish1

I think you’ve got your ppm and % muxed ip a few times but I think you are looking for “You will never maintain 100%, assuming its consuming 1.5ppm per day”.

 

[coral reeftank]

Assuming that the mix is 100ppm, and that you only rely on water changes, I don’t think that you will be able to reach 400 ppm again, as you would end up with 100 ppm solution even if you go beyond a 100 percent wc.

 

[Reefahholic]

Assuming that the mix is 100ppm, and that you only rely on water changes, I don’t think that you will be able to reach 400 ppm again, as you would end up with 100 ppm solution even if you go beyond a 100 percent wc.

Are you sure? You don’t sound confident and there was an edit. HaHa…

 

[Reefahholic]

**Let’s rewrite this…it should be easier.** I may have worded it wrong.

Element X = 100 ppm

Your 100/G system is growing rapidly and consuming 10 ppm of Element X each week. We have already tested our salt-mix and confirmed that Element X is present in the salt. We found the concentration at 100 ppm. Element X was initially at 100 ppm, but now has dropped to 90 ppm. You rely solely upon water changes for supplementation of all elements.

What % of water needs to be changed to replenish Element X back to 100% or 100 ppm?

I know @rtparty can answer this, but maybe wait to see what kind of answers are given. I’ve been up for 16 hrs now so my brain needs to take a break for now. I’ll check back tomorrow evening.

 

[Garf]

**Let’s rewrite this…it should be easier.** I may have worded it wrong.

Element X = 100 ppm

Your 100/G system is growing rapidly and consuming 10 ppm of Element X each week. We have already tested our salt-mix and confirmed that Element X is present in the salt. We found the concentration at 100 ppm. Element X was initially at 100 ppm, but now has dropped to 90 ppm. You rely solely upon water changes for supplementation of all elements.

What % of water needs to be changed to replenish Element X back to 100% or 100 ppm?

I know @rtparty can answer this, but maybe wait to see what kind of answers are given. I’ve been up for 16 hrs now so my brain needs to take a break for now. I’ll check back tomorrow evening.

100% water change, to return it to 100ppm, lol

 

[Reefahholic]

100% water change, to return it to 100ppm, lol

Ha! So you mean I need to change 100% of my water weekly to get Element X from 90 ppm back too 100 ppm!

Let’s make it even more interesting.

What happens in a super fast growing 5-10 yr old Acropora dominated system where biomass now accounts for 50% of the 100/G system volume, and Element X is now being consumed at 20 ppm a week instead of 10 ppm. You mean now we need to do 200% water changes weekly to make sure Element X is back in there.?! Ouch!

Anybody have a change of mind about water changes?

 

[Dan_P]

Element X = 100 ppm

Your system is growing rapidly and consuming 10 ppm of Element X each week. We have already tested our salt-mix and confirmed that Element X is present in the salt. We found the concentration at 100 ppm. Element X was initially at 400 ppm, but now has dropped to 390 ppm. You rely solely upon water changes for supplementation of all elements.

What % of water needs to be changed to replenish Element X back to 100% or 400 ppm?

@rtparty
@Hans-Werner
@Randy Holmes-Farley
@MnFish1

Just to confirm the query.

The new salt mix is 100 ppm element X.

The aquarium is currently at 390 ppm but you want 400 ppm element X.

You want to know how much 100 ppm element X to exchange with 390 ppm to achieve 400 ppm

Right?

 

[Reefahholic]

Just to confirm the query.

The new salt mix is 100 ppm element X.

The aquarium is currently at 390 ppm but you want 400 ppm element X.

You want to know how much 100 ppm element X to exchange with 390 ppm to achieve 400 ppm

Right?

Basically, but I think it’s easier to think about it like this. So I rewrote it like this below:

Element X = 100 ppm

Your 100/G system is growing rapidly and consuming 10 ppm of Element X each week. We have already tested our salt-mix and confirmed that Element X is present in the salt. We found the concentration at 100 ppm. Element X was initially at 100 ppm, but now has dropped to 90 ppm. You rely solely upon water changes for supplementation of all elements.

What % of water needs to be changed to replenish Element X back to 100% or 100 ppm?

————————————————————-
My goal here was to try and illustrate how much water is actually needed to replenish elements, because you always hear reefers claiming that 10% water changes every week solve everything.

They are great from removing pollutants, especially those we can’t test for. They’re also beneficial for reefers who are unable to manage nutrients, but not so good at adding elements back unless you’re changing significant volumes.

I got started on this topic because of @rtparty’s salt testing experiment and it really got me thinking. I was trying to illustrate his logic, but I couldn’t remember exactly how he worded it, but I finally found his reply in one of my threads from a while back.

 

[DIFish]

Yes, your water is constantly getting less of x slowly over time with stable water changes assuming the consumption rate does not change. Water changes taper the effect more with higher % changes, but if the water going in is equal to or under your goal amount then no change under 100% will get you back to the salt baseline. Ways around this are to dose or to use salt that is above your expected levels. For example if you want 8 DKH Alk and your table used 1 per week and your salt mixes at 8, you will never get back to 8 without a 100% change, but if your salt mixes at 10 you can get back with consistent large changes.

Edit- Check out this tool for an example

Aquarium Water Change Calculator | BeanAnimal's Reef

Use this aquarium water change calculator to chart how a given water parameter will rise or fall over the course of multiple water changes.

beananimal.com

 

[Randy Holmes-Farley]

As folks have noted, water changes shy of 100% changed at once cannot ever maintain a starting level of any compound against consumption.

That said, many elements may not need to be maintained at the starting level, and if the salt mix has some extra (as many do for alk, calcium, and magnesium) then water changes may provide "enough" in some cases.

 

[Reefahholic]

I hope reefers consider this in the future. It’s not that water changes don’t work or can’t be beneficial, it’s because people have promoted them as if 10% is all you need. That may be the case for a new system that’s not growing well, but when the system takes off many elements will become depleted rapidly.

IMO, if you’re relying on water changes alone, make sure you’re changing a large enough volume. I think large auto water changes would be the way to go, or at least send an analysis out to see where the levels actually are. Like Randy said, if you’re using a salt that has 11 dKH ALK, 1500 mag, and 450 CAL….those major elements may get very high quickly especially if you’re dosing them as well. A lot of things to consider here. The smart thing to do is check on the elements, and do the math.

 

[Reefahholic]

Yes, your water is constantly getting less of x slowly over time with stable water changes assuming the consumption rate does not change. Water changes taper the effect more with higher % changes, but if the water going in is equal to or under your goal amount then no change under 100% will get you back to the salt baseline. Ways around this are to dose or to use salt that is above your expected levels. For example if you want 8 DKH Alk and your table used 1 per week and your salt mixes at 8, you will never get back to 8 without a 100% change, but if your salt mixes at 10 you can get back with consistent large changes.

Edit- Check out this tool for an example

Aquarium Water Change Calculator | BeanAnimal's Reef

Use this aquarium water change calculator to chart how a given water parameter will rise or fall over the course of multiple water changes.

beananimal.com

That is an interesting tool. Never seen it before, but I know @BeanAnimal has been the game for a long time.