Stable parameters.. how often to change water?

[780blaster]

For the last 2 or 3 months, my parameters have been very stable without doing water changes. I’ve been doing some water changes here and there but definitely not weekly. When I do, my nitrates and phosphates get lower than I would like (I was at 0 and 0 for a while when everything was getting going so I just don’t want to crash it). I dose a bit to bring those numbers back up.

I think the reason the numbers stay pretty constant is because I have an assortment of macroalgae in the sump.

Anyways, typical numbers are:

Salinity: 1.025
N03: 5ppm
Po4: 0.03ppm
Alk: 8.5 dkh
Calcium: 415
Temp: 78F

I dose reef code a/b twice daily to maintain alk and calcium

Everything seems pretty happy minus a couple LPS corals but I think that might be a flow or lighting issue. Other LPS of the same species are doing awesome. Even some easier SPS doing great.

Anyways, what should I be doing for water changes? 10% weekly but dose nitrates and phosphates back up? Every second week?

It’s probably been 3 weeks since I did a 15% water change. All is good still, only negative is I noticed some black beard algae which is kind of what prompted the question. I’ll remove this manually but not sure if it’s related or not seeing as my parameters seem good

 

[Johnd651]

For the last 2 or 3 months, my parameters have been very stable without doing water changes. I’ve been doing some water changes here and there but definitely not weekly. When I do, my nitrates and phosphates get lower than I would like (I was at 0 and 0 for a while when everything was getting going so I just don’t want to crash it). I dose a bit to bring those numbers back up.

I think the reason the numbers stay pretty constant is because I have an assortment of macroalgae in the sump.

Anyways, typical numbers are:

Salinity: 1.025
N03: 5ppm
Po4: 0.03ppm
Alk: 8.5 dkh
Calcium: 415
Temp: 78F

I dose reef code a/b twice daily to maintain alk and calcium

Everything seems pretty happy minus a couple LPS corals but I think that might be a flow or lighting issue. Other LPS of the same species are doing awesome. Even some easier SPS doing great.

Anyways, what should I be doing for water changes? 10% weekly but dose nitrates and phosphates back up? Every second week?

It’s probably been 3 weeks since I did a 15% water change. All is good still, only negative is I noticed some black beard algae which is kind of what prompted the question. I’ll remove this manually but not sure if it’s related or not seeing as my parameters seem good

What size tank?

You will get a variety of answers, depending on what methods other people use from never to weekly.

The one thing I try to keep in mind is what are we not measuring in the hobby that may be building up week over week. I've always tried to do 20% every 2 weeks, but it's on a 15 gallon.

There are some people that also do continous water changes, the idea being that it's a constant dilution.

Just a couple thoughts.

 

[780blaster]

What size tank?

You will get a variety of answers, depending on what methods other people use from never to weekly.

The one thing I try to keep in mind is what are we not measuring in the hobby that may be building up week over week. I've always tried to do 20% every 2 weeks, but it's on a 15 gallon.

There are some people that also do continous water changes, the idea being that it's a constant dilution.

Just a couple thoughts.

Fair enough.

I have about a 75 gal display + 25-30 gal sump

 

[Randy Holmes-Farley Verified Community Expert]

I change water 3 times a day, using an AWC, totaling 1% daily.

 

[780blaster]

I change water 3 times a day, using an AWC, totaling 1% daily.

If you didn’t change any water would your nitrate and phosphates stay at a healthy level?

 

[Randy Holmes-Farley Verified Community Expert]

If you didn’t change any water would your nitrate and phosphates stay at a healthy level?

Yes. The effect on nutrients is pretty small, and is not a reason I do water changes. :)

 

[Malum Argenteum]

Everything seems pretty happy minus a couple LPS corals but I think that might be a flow or lighting issue. Other LPS of the same species are doing awesome. Even some easier SPS doing great.

This is the main hook on which to hang your maintenance schedule. Parameters can often tell you why the livestock is looking good or bad, but it is that livestock that knows best how much water changing they need.

 

[780blaster]

This is the main hook on which to hang your maintenance schedule. Parameters can often tell you why the livestock is looking good or bad, but it is that livestock that knows best how much water changing they need.

Good point there.

Did you mean though that I should be doing more changes because some aren’t doing great?

Or stick to what’s been working for the ones that are super happy?

 

[780blaster]

Yes. The effect on nutrients is pretty small, and is not a reason I do water changes. :)

Sounds good, thanks for the tips!

 

[Malum Argenteum]

Good point there.

Did you mean though that I should be doing more changes because some aren’t doing great?

Or stick to what’s been working for the ones that are super happy?

I meant watch your corals at least as much as you watch your parameters. How you interpret the corals' behavior is up to you, but my point is that that's what ultimately matters.

You mentioned a couple corals might have flow or lighting issues, which very well may be true. But you may want to try a water change here or there and see if anything changes, or even a regular schedule of small water changes where you see how your livestock reacts over time. Every tank's different, and every reefkeeper has their own approach.

 

[LovinlifeinGuam]

Keep in mind that water changes replenish trace elements as well.

 

[gbroadbridge]

For the last 2 or 3 months, my parameters have been very stable without doing water changes. I’ve been doing some water changes here and there but definitely not weekly. When I do, my nitrates and phosphates get lower than I would like (I was at 0 and 0 for a while when everything was getting going so I just don’t want to crash it). I dose a bit to bring those numbers back up.

I think the reason the numbers stay pretty constant is because I have an assortment of macroalgae in the sump.

Anyways, typical numbers are:

Salinity: 1.025
N03: 5ppm
Po4: 0.03ppm
Alk: 8.5 dkh
Calcium: 415
Temp: 78F

I dose reef code a/b twice daily to maintain alk and calcium

Everything seems pretty happy minus a couple LPS corals but I think that might be a flow or lighting issue. Other LPS of the same species are doing awesome. Even some easier SPS doing great.

Anyways, what should I be doing for water changes? 10% weekly but dose nitrates and phosphates back up? Every second week?

It’s probably been 3 weeks since I did a 15% water change. All is good still, only negative is I noticed some black beard algae which is kind of what prompted the question. I’ll remove this manually but not sure if it’s related or not seeing as my parameters seem good

Macro Elements and Waste products that you can measure are not the whole story.

There are a whole bunch of trace elements, plus other organics that you cannot measure that are also of some concern. They can be depleted or they could be building up to harmful levels.

There is an argument that the larger the tank the greater the likelihood that the system can be self sustaining and balanced.

Conversely the other argument is that if you do regular water changes, or continuous water changes, you are diluting those changes which can only be good.

I find in my small nano which has over time gained a large bioload - I see nuisance algae and cyonobacteria breakouts if I skip 10% water changes each week.

My other 90 gal system which is more mature seems happy with 10% a month.