Reducing Nitrates and Phosphates via Water Change Help

[ReeferWarrant]

Setting up to reduce my nitrates which are at 40 ppm and I want to get them down to around 10 ppm. I currently have mostly soft and LPS corals, but tried introducing some Monti's, which are extending but I dont believe they are doing well. Additionally, my Phosphate is high so my assumption is that a Water Change (WC) would reduce these levels. The question is do I continue to do a daily 10% WC or should I do a 30% WC (limited by buckets I have) in one go?

Thanks in advance!

 

[Spare time]

You could try something like waste away or similar to lower them. How big is the tank?

 

[ReeferWarrant]

32 Gallon, I neglected doing water changes while I was traveling for work so its probably not a bad idea for just doing a WC

 

[Spare time]

32 Gallon, I neglected doing water changes while I was traveling for work so its probably not a bad idea for just doing a WC

A big water change should be fine. It would probably be handy for all sorts of reasons. I wouldnt worry as long as the salinity and temp of the mixed water matches the tank. Id only be worried if you have lps or sps since you coule be shining the alk back up if you didn't dose alk. For future reference, try dr tims waste away gel. It will keep nitrate and phosphate under control if you have to be gone for a while.

 

[NeptuneRjo]

Doing a larger wc will result in an immediate and larger drop in nutrient levels. Imo you should do the 30% and see where you are, then decide whether or not to do another or continue on with 10% changes.

 

[ReeferWarrant]

@Spare time Awesome! I'll order some today, I keep trying to do a small refugium with Chaeto in the back and it fails every time. I think its time to quit that option so the Waste Away should be a good route for me.

@NeptuneRjo 30% and 10% sounds like a smart route to go, thanks for the input. Now to mix up some salt.

 

[Spare time]

Chaeto sometimes dies if the light is too weak of if it runs out of trace elements (the ladder of the two is what i have encountered before)

 

[Wildreefs]

Water changes are the worst way to lower anything that bullds up long term.

Something foreign like a metal , or substance put in out out of the norm (meds, supplement placed in that isn’t the norm, etc) sure will work with the expectation you aren’t going to add them in continually.

However things that just accumulate as part
Of ongoing tank life (feeding), will impossible to keep up, unless you do 100 percent water change.

Think of it this way. You have ten fish that eat 40 cubes total a week. This equates to x amount of ammonia (5 ppm in 100 gallons) which turned into 10 nitrates a week.

So you start with new 0 water, new tank. After 1 week, you’re at 10 nitrates. You do a 50 percent water change (larger than most would do), and brings your nitrates down to 5z

Week two you start at 5, but thru the aforementioned feeding regimen for said fish, you add 10 more nitrates, so no it’s 15 total.

Another 50 percent water change, and you go down to 7.5, week later you add ten more nitrate, and end up 17.5 nitrate ,another 50 percent water change, now your at 9.

You can see the trend, air of salt, and in 3-4 months your at 50 nitrates, which will only continue to rise.

 

[ReeferWarrant]

@Wildreefs, that's probably how I'm at 40 ppm. Good explanation, I never put the math in my mind behind what the WC's were doing until recently. That's why I was tempted with a larger change to reduce the levels.

 

[Wildreefs]

You can do 50 percent every day, for the next year, unless you get it to absolute 0 (100 percent water change) it will always rise, just slower with more changes. Because you are never zeroing it out .

Need something that pulls them out to 0 constantly. I use a biodenitrator, and went from 50 to 5 in 2 months, with minimal water changes

 

[Wildreefs]

And I’m sorry about the grammar on the first response there. iPhone sucks for typing long paragraphs.

Moral tot he story is unless you start at 0 at some point, by a total water change, it’s just an uphill graph. I went thru many boxes of salt before I realized the math won’t add up doing it this way.

 

[chipmunkofdoom2]

Water changes are not effective at remediating high phosphates. Phosphates bind to calcium carbonate surfaces like rock and sand. If you did a 100% WC, phosphates will release from the rock and drive the numbers up again.

 

[Biokabe]

Regular water changes have their place, but they shouldn't be thought of as a regular form of nutrient export. They can be effective as an emergency way to quickly reduce levels, but not as a persistent method unless your water change schedule outpaces your nutrient production rate.

Far better to figure out the appropriate level of feeding, balance it out with CUC and add a reliable form of nutrient export, such as a refugium, ATS and/or skimmer.

When building your CUC, don't solely focus on algae eaters. You need detrivores as well. The more bodies a piece of food passes through, the less waste is left over at the end. If the same piece of food can be used to feed a fish, a hermit, a snail, a starfish, a conch, a sea cucumber, an isopod, and a copepod, you'll end up with less junk in your water than if it just passes through a fish and then onto your sandbed.

 

[mindme]

Water changes are the worst way to lower anything that bullds up long term.

Something foreign like a metal , or substance put in out out of the norm (meds, supplement placed in that isn’t the norm, etc) sure will work with the expectation you aren’t going to add them in continually.

However things that just accumulate as part
Of ongoing tank life (feeding), will impossible to keep up, unless you do 100 percent water change.

Think of it this way. You have ten fish that eat 40 cubes total a week. This equates to x amount of ammonia (5 ppm in 100 gallons) which turned into 10 nitrates a week.

So you start with new 0 water, new tank. After 1 week, you’re at 10 nitrates. You do a 50 percent water change (larger than most would do), and brings your nitrates down to 5z

Week two you start at 5, but thru the aforementioned feeding regimen for said fish, you add 10 more nitrates, so no it’s 15 total.

Another 50 percent water change, and you go down to 7.5, week later you add ten more nitrate, and end up 17.5 nitrate ,another 50 percent water change, now your at 9.

You can see the trend, air of salt, and in 3-4 months your at 50 nitrates, which will only continue to rise.

I disagree. Water changes can fix most anything. And they are my main method of nutrient export not counting skimmers etc, which I'm sure the OP also has since we are talking about excess nutrients.

Your math is right, but it won't continue to rise forever. Eventually it will reach a point where you can remove as much as you add. And how much a water change helps will depend alot on load.

Because lets say you get the 10ppm per week as in your example. While getting it to 0 isn't possible without 100% water change, you can formulate a % of water to change to remove the 10ppm and eventually reach a stable point.

To remove 10ppm per week and maintain the number each week(removes 10ppm with each water change):

10ppm you need a 100% water change
20ppm you need a 50% water change.
30ppm you need a 33% water change.
40ppm you need a 25% water change.
etc

It eventually equals out.

But 10ppm seems like a lot to add in a week. If it's just like 2 then it's much more manageable, and for me that still seems a little high.

Same thing as above, but only 2ppm added a week:
At 10ppm you need only a 20% water change to remove the 2ppm and you can maintain a nitrate level of 8 - 10ppm during the week.

Much lower demand on the water change numbers. 50% as in your example would keep you well under 10ppm nitrates.

Water changes work. But I guess if you are adding extreme amounts of nitrates like 10ppm per week then you're not going to balance out until a much higher level.

 

[mindme]

Setting up to reduce my nitrates which are at 40 ppm and I want to get them down to around 10 ppm. I currently have mostly soft and LPS corals, but tried introducing some Monti's, which are extending but I dont believe they are doing well. Additionally, my Phosphate is high so my assumption is that a Water Change (WC) would reduce these levels. The question is do I continue to do a daily 10% WC or should I do a 30% WC (limited by buckets I have) in one go?

Thanks in advance!

Do water changes until you get the number you want. The higher the number the better IMO, as long as you aren't stressing your corals out. If you have a huge tank, then 30% might be a lot of volume to move around and not something you want to do. But if it's something you can pull off, then it will help a lot. You are literally removing the nitrates with each water change. 10% still works also, just takes more water changes to reach the same goal.

If you want to find out how much water you need to change to maintain a certain number, you just need to figure out how much of the nutrient you are getting over the time period and do the math I did above.

 

[Stigigemla]

Having that high values I wouldnt do large waterchanges in order not to shock the corals.
I would change 10% each day in 2 weeks in order to be under 10 mg/l nitrate. And then make it twice a week. Then I would test the phosphate and if it is more than 0.1 I woud use GFO in a sock. Take up the sock 2 times a week and move around the content a little. I would start with about 2 ounce in the sock and replace it after 2 weeks. When the value is at 0.1 or under I will half the amount of GFO. The best test for phosphate is Hanna checker as it has much better resolution so You can see a reduction of a few %. A color chart test has colors for half or double the value and that is how precise they are. That precision is normally good enough but You cant see if You lowered the value 10%.

 

[ReeferWarrant]

I went with the 30% and now doing 10% daily after each reading. I'm using a color coded test kit so when I tested Nitrate it's getting in the 20 ppm coloration which is a positive direction if correct. All other parameters are fairly close to what they were prior.

Before:
Ca: 390 ppm
Alk: 8.9
Mg: 1320 ppm

After:
Ca: 415 ppm
Alk: 8.7
Mg: 1260 ppm

One bad/adverse thing that occured when I did this, my tuxedo urchin was on the glass and fell into the sand bed. I guess that stressed it and it began to spawn..... All of the parameters to include salinity and temperature stayed close if not the same. Going to do another WC today since it decided to add more into the water for me...


So far so good though, Thanks again for the input!

 

[mike550]

I went with the 30% and now doing 10% daily after each reading. I'm using a color coded test kit so when I tested Nitrate it's getting in the 20 ppm coloration which is a positive direction if correct. All other parameters are fairly close to what they were prior.

Before:
Ca: 390 ppm
Alk: 8.9
Mg: 1320 ppm

After:
Ca: 415 ppm
Alk: 8.7
Mg: 1260 ppm

One bad/adverse thing that occured when I did this, my tuxedo urchin was on the glass and fell into the sand bed. I guess that stressed it and it began to spawn..... All of the parameters to include salinity and temperature stayed close if not the same. Going to do another WC today since it decided to add more into the water for me...


So far so good though, Thanks again for the input!

For what it's worth, I had a similar situation where my nitrates were too high. I ended up making three 30% water changes over the course of three days, and now I'm making 10% weekly changes. So far so good. My point is that if the 10% daily changes aren't working fast enough or you're losing ground, don't be afraid of making "bigger" changes quickly.

Not sure if you've seen it, but there's a pretty cool water change calculator. Hopefully this link works -- otherwise it's on hamzasreef.com

Effect of Water Changes Calculator

Aquarium calculator; Estimate the effect of repeated water changes on the concentration of a given substance.

www.hamzasreef.com

 

[jda]

You can get the nitrate down with water changes, but phosphate is going to be harder. It will take a few days for the rock/sand to release bound P after the water change - if your P is high, then there can be quite a bit of P bound in the aragonite. You might need to use some GFO or Lan Chloride after you get the N where you want it - go slow and all of this is OK.

 

[Daddy-o]

Water changes are the worst way to lower anything that bullds up long term.

Something foreign like a metal , or substance put in out out of the norm (meds, supplement placed in that isn’t the norm, etc) sure will work with the expectation you aren’t going to add them in continually.

However things that just accumulate as part
Of ongoing tank life (feeding), will impossible to keep up, unless you do 100 percent water change.

Think of it this way. You have ten fish that eat 40 cubes total a week. This equates to x amount of ammonia (5 ppm in 100 gallons) which turned into 10 nitrates a week.

So you start with new 0 water, new tank. After 1 week, you’re at 10 nitrates. You do a 50 percent water change (larger than most would do), and brings your nitrates down to 5z

Week two you start at 5, but thru the aforementioned feeding regimen for said fish, you add 10 more nitrates, so no it’s 15 total.

Another 50 percent water change, and you go down to 7.5, week later you add ten more nitrate, and end up 17.5 nitrate ,another 50 percent water change, now your at 9.

You can see the trend, air of salt, and in 3-4 months your at 50 nitrates, which will only continue to rise.

I am thinking that this is not entirely correct. We would need to know the rate that the current bacteria population is removing nitrates from the water? The 40ppm nitrate that the OP has is excess that the bacteria cant currently remove. If you do regular water changes, it will remove the excess and not raise nitrates. Along with regular maint, proper nutrient removal, and perhaps small more frequent meals there is no reason the nitrates wont go down.
Cheers! Mark