onmyway
New Member
Hey Reefers -
I wanted to reduce my phosphates and nitrates by half, but I didn't want to create a shock to the system with a 50% water change in 1 day, and I only have the physical equipment to change out so many gallons at a time, so I thought I'd sequence it while I had the downtime. So the rest of the post is a series of nerdy declarative statements, but what I'm really asking is whether (1) other people look at it this way and/or (2) whether I'm actually thinking about it correctly.
My initial concern was that by changing my water over multiple days, each new water change is actually just swapping out a mix of previously changed water, in addition to old tank water.
I'm sure it'd be easy to check the nutrients after consistent water changes and stop when they're at the desired level, but I also wanted to know if some quick math could help me plan for the desired outcome in advance. Plus, if I wanted easy, I don't think I would have tried to recreate a 400M year old Indo Pacific eco-system in my Chicago living room.
That being said, here are some variables for easier math:
1) 100G of water (after accounting for display, sump and rock/substrate displacement)
2) 10G water change per day
On Day 1, I swap out 10G. I've completed a 10% water change (hooray)
On Day 2, I swap out 10G, I've completed an 18% change because my Day 2 water is a 90%/10% mix of old/new water
*rinse and repeat*
By Day 6, my 60th gallon (or 60% change) is reduced to an effective change of 39% which means that if it hasn't already, then surely by Day 10, when my 100% water change only changed out 51.3%%, there are probably enough nutrients in the *newer* water that I'm excluding, and it'll be hard to truly preplan a 50% reduction in NO3/PO4.
My actual variables are a bit different, but I was curious if people go through exercises like this or if it's just a matter of the first option -- i.e., change + levels check + change + levels check and stopping when you're happy.
Thank you if you read this far and look forward to some responses.
OMW
I wanted to reduce my phosphates and nitrates by half, but I didn't want to create a shock to the system with a 50% water change in 1 day, and I only have the physical equipment to change out so many gallons at a time, so I thought I'd sequence it while I had the downtime. So the rest of the post is a series of nerdy declarative statements, but what I'm really asking is whether (1) other people look at it this way and/or (2) whether I'm actually thinking about it correctly.
My initial concern was that by changing my water over multiple days, each new water change is actually just swapping out a mix of previously changed water, in addition to old tank water.
I'm sure it'd be easy to check the nutrients after consistent water changes and stop when they're at the desired level, but I also wanted to know if some quick math could help me plan for the desired outcome in advance. Plus, if I wanted easy, I don't think I would have tried to recreate a 400M year old Indo Pacific eco-system in my Chicago living room.
That being said, here are some variables for easier math:
1) 100G of water (after accounting for display, sump and rock/substrate displacement)
2) 10G water change per day
On Day 1, I swap out 10G. I've completed a 10% water change (hooray)
On Day 2, I swap out 10G, I've completed an 18% change because my Day 2 water is a 90%/10% mix of old/new water
*rinse and repeat*
By Day 6, my 60th gallon (or 60% change) is reduced to an effective change of 39% which means that if it hasn't already, then surely by Day 10, when my 100% water change only changed out 51.3%%, there are probably enough nutrients in the *newer* water that I'm excluding, and it'll be hard to truly preplan a 50% reduction in NO3/PO4.
My actual variables are a bit different, but I was curious if people go through exercises like this or if it's just a matter of the first option -- i.e., change + levels check + change + levels check and stopping when you're happy.
Thank you if you read this far and look forward to some responses.
OMW
