How much water to change in a 50 gallon

[FRANK48]

I have a 50 gallon tank with 8 fish and coral and I usually change 25 gallons of water every two weeks.
Is this too much and if so how much water should I be taking out and putting in.

thanks

 

[bnord]

An alternate approach would be 10% each week. Adds to the consistency Of the system

 

[FRANK48]

An alternate approach would be 10% each week. Adds to the consistency Of the system

So change 5 gallons every week?

 

[Waters]

It entirely depends on your nutrient levels in your tank. There are pico tanks that change 100% of the water at a time as well as tanks that don't do any water changes at all. If your nitrate/phosphates are in line, I would recommend smaller amounts weekly just to replace lost trace elements (3-5 gallons). If you have issues with elevated nutrients, I would change larger amounts weekly.

 

[FRANK48]

It entirely depends on your nutrient levels in your tank. There are pico tanks that change 100% of the water at a time as well as tanks that don't do any water changes at all. If your nitrate/phosphates are in line, I would recommend smaller amounts weekly just to replace lost trace elements (3-5 gallons). If you have issues with elevated nutrients, I would change larger amounts weekly.

Okay thanks. Because usually I test and my phosphates are always zero and nitrates are at 5.

 

[Waters]

Okay thanks. Because usually I test and my phosphates are always zero and nitrates are at 5.

Then I would definitely stick to smaller water changes. You might even want to just do 5 gallons every two weeks and test to see where you are at.

 

[Jekyl]

I have 8 fish in a 90g and I'll do a 30% change every few months. Parameters dictate the changes needed.

 

[FRANK48]

I have 8 fish in a 90g and I'll do a 30% change every few months. Parameters dictate the changes needed.

Well currently my alk is at 7.3 so I was thinking if I needed to do a water change.

 

[Jekyl]

Well currently my alk is at 7.3 so I was thinking if I needed to do a water change.

If only concerned about alkalinity why not just dose it? Can be accomplished with every day baking soda.

 

[bnord]

So change 5 gallons every week?

as you can see there is no exactitude (first time I have typed that word) on the science.

I would suggest you set up a modest (10%/5 gallons) on a weekly schedule - carry forward with it while you look at your tanks' health and well being, and water parameters - with that you can adjust feeding and filtration to your tanks needs.
Is you water home made - or LFS sourced?
Consistency above all else!

 

[FRANK48]

as you can see there is no exactitude (first time I have typed that word) on the science.

I would suggest you set up a modest (10%/5 gallons) on a weekly schedule - carry forward with it while you look at your tanks' health and well being, and water parameters - with that you can adjust feeding and filtration to your tanks needs.
Is you water home made - or LFS sourced?
Consistency above all else!

My water is homemade

 

[MickeyR]

I'm odd, I used to chase numbers, no I dont even test anything unless something seems off. I change water every 2-4 months and do a 20% change when I do it. If you have issues address them, if you have no issues then why worry. I even went completely skimmer less because of my skimmer being too strong and bringing down everything to 0.

 

[FRANK48]

I'm odd, I used to chase numbers, no I dont even test anything unless something seems off. I change water every 2-4 months and do a 20% change when I do it. If you have issues address them, if you have no issues then why worry. I even went completely skimmer less because of my skimmer being too strong and bringing down everything to 0.

Did you dose?

 

[CaffeinatedReefer]

Okay thanks. Because usually I test and my phosphates are always zero and nitrates are at 5.

I’d definitely recommend the less is more thing here. Had a 40 gal in the early years. I was doing 5 gallons every week. Religiously. Boom! Dinoflagellates.
Five gallons every couple weeks is likely sufficient. If you’re worried about alk, dosing is easy peasy.

 

[MickeyR]

Did you dose?

I just dose 2 part calc/alk b-ionic and red sea ab+

 

[Lost in the Sauce]

Okay thanks. Because usually I test and my phosphates are always zero and nitrates are at 5.

Well yeah. You're pulling 50 % of the water out every two weeks. Most do 20% every two weeks or 10%\week.

 

[FRANK48]

I’d definitely recommend the less is more thing here. Had a 40 gal in the early years. I was doing 5 gallons every week. Religiously. Boom! Dinoflagellates.
Five gallons every couple weeks is likely sufficient. If you’re worried about alk, dosing is easy peasy.

Dosing to me is quite intimidating and im not sure when to start or if I have to

 

[Lost in the Sauce]

If only concerned about alkalinity why not just dose it? Can be accomplished with every day baking soda.

7.3 is likely much lower DKH than the salt mixes to.

Think about the swings if using IORC. Mine test near the top of 10. My tank would be ticked going 7 to 10 every 2 weeks.

Rather than adding a doser, Smaller weekly water change would help flatten the alkalinity trend as well as help retains some of the nutrients to get them above zero.

 

[MickeyR]

Dosing to me is quite intimidating and im not sure when to start or if I have to

There are some calculators online, I just dosed and tested for a couple of weeks to check calc/alk/mag. I wanted to do kalk, but couldnt find a good way to do that with my ato, instead got a jebao wifi doser and started slow and increased it. I do think I will have to do something more as my calcium demands will get more and more overtime with more growth.

 

[FRANK48]

7.3 is likely much lower DKH than the salt mixes to.

Think about the swings if using IORC. Mine test near the top of 10. My tank would be ticked going 7 to 10 every 2 weeks.

Rather than adding a doser, Smaller weekly water change would help flatten the alkalinity trend as well as help retains some of the nutrients to get them above zero.

Okay thanks I think I’ll start doing 5 gallons every week