3 Questions About Water Changes

jscott

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1. At the end of cycling a tank, using fish food, without fish, I need to do a light vacuuming and water change, correct? What percentage water change?
2. Do you always dose for the whole tank when using Prime during water changes?
3. When starting out, How do you know how often to do water changes? Do you go by the nirtrate reading? (My tank will not be fully stocked until 3-4 months, adding just two fish at a time.) Some say always weekly, one guy at the LFS store said monthly, which was surprising because he seemed extremely knowledgeable.

Thanks in advance! Y'all are the best.
 

Aster

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1. I would do a large enough water change to bring nitrates down to 20ppm.
2. If you are adding water directly to the tank, dose for the entire tank. If you are adding Prime to the water before putting it in, dose for the amount you're putting in.
3. I always do 50% weekly, water changes not only lower nitrates but replenish minerals. I think it's better to be safe than sorry.
 

Lchi87

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1. Depends on how the tank looks and your parameters. If you see the floor littered with fish food, then yes, a gravel vac is in order. Your nitrates should be kept below 20.

2. Yes, I dose the whole tank volume. Easier than trying to dose only the amount I changed!

3. I do mine weekly at least. A lot of LFS say monthly. I wouldn't just go by nitrate readings since there are other nutrients and minerals in the water column you don't test for that are regularly depleted that benefit from being replenished.

Hope that helps!
 
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jscott

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Lchi87 said:
1. Depends on how the tank looks and your parameters. If you see the floor littered with fish food, then yes, a gravel vac is in order. Your nitrates should be kept below 20.

2. Yes, I dose the whole tank volume. Easier than trying to dose only the amount I changed!

3. I do mine weekly at least. A lot of LFS say monthly. I wouldn't just go by nitrate readings since there are other nutrients and minerals in the water column you don't test for that are regularly depleted that benefit from being replenished.

Hope that helps!
That definitely helps, and makes a lot of sense! It's hard when researching and reading contradictory things, but that clears it up quite a bit.
 

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1. Agree with everyone else. I usually cycle with Seachem Stability, which helps make sure you don't lose your cycle by accident. I'd look it up if you're having trouble maintaining a cycle.

2. Dose for the whole tank. Won't hurt the fish, and will trap some ammonia for you as well. If the cost of Prime starts to add up, I'd look into Seachem Safe. Same thing, powdered form. Way more bang for your buck.

3. Depending on your tank, you could do monthly water changes. But many factors come into play. Is your tank planted? How heavy of a stock do you have, and what type of fish? Are you chemically filtering? I know some people that rarely change water, and their parameters are fine. It's all about finding a good balance. If you're just starting out, weekly should be just fine.

I'm curious, what type of fish are you adding 2 at a time? Many schooling fish will have trouble in small groups like that, and it could cause trouble maintaining your cycle if you add fish in this fashion. You may have a perfectly fine reason for doing it this way, just wondering!
 

bNissan

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Everybody's tank is a little bit different when it comes to water changes. What has worked for me is dedicating a 5 gallon bucket to water changes (or more if required). I put in the right amount of water conditioner for the contents of the bucket and let it sit 12-24 hours. This way I don't waste conditioner/money.

I also input the size of my tank, my filters, and my fish into the aqua advisor calculator and care for my water as it advises. The calculator generates information based on the bio-load of full grown fish, and in my experience has been spot on.

Also, if you are adding schooling fish it would be best to add no fewer than 6 as loneliness might cause them undue stress.
 

Fishbeard

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bNissan said:
Everybody's tank is a little bit different when it comes to water changes. What has worked for me is dedicating a 5 gallon bucket to water changes (or more if required). I put in the right amount of water conditioner for the contents of the bucket and let it sit 12-24 hours. This way I don't waste conditioner/money.

I also input the size of my tank, my filters, and my fish into the aqua advisor calculator and care for my water as it advises. The calculator generates information based on the bio-load of full grown fish, and in my experience has been spot on.

Also, if you are adding schooling fish it would be best to add no fewer than 6 as loneliness might cause them undue stress.
Agree with all of that bNissan. I wish there were universal answers to all these questions, but sometimes you need more info to give good responses!
 
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jscott

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Fishbeard said:
1. Agree with everyone else. I usually cycle with Seachem Stability, which helps make sure you don't lose your cycle by accident. I'd look it up if you're having trouble maintaining a cycle.

2. Dose for the whole tank. Won't hurt the fish, and will trap some ammonia for you as well. If the cost of Prime starts to add up, I'd look into Seachem Safe. Same thing, powdered form. Way more bang for your buck.

3. Depending on your tank, you could do monthly water changes. But many factors come into play. Is your tank planted? How heavy of a stock do you have, and what type of fish? Are you chemically filtering? I know some people that rarely change water, and their parameters are fine. It's all about finding a good balance. If you're just starting out, weekly should be just fine.

I'm curious, what type of fish are you adding 2 at a time? Many schooling fish will have trouble in small groups like that, and it could cause trouble maintaining your cycle if you add fish in this fashion. You may have a perfectly fine reason for doing it this way, just wondering!
Thanks, I ordered some Stability today, to help make sure the cycle will complete itself. I am adding schooling fish, and I hate adding two at a time, but everything I've read said to do that so you don't overwhelm the bioload... What do you suggest? 3 or 4? My ultimate goal is 8 Cardinals, 6 cories, 1 dwarf gourami, and maybe 6 cherry shrimp.

bNissan said:
Everybody's tank is a little bit different when it comes to water changes. What has worked for me is dedicating a 5 gallon bucket to water changes (or more if required). I put in the right amount of water conditioner for the contents of the bucket and let it sit 12-24 hours. This way I don't waste conditioner/money.

I also input the size of my tank, my filters, and my fish into the aqua advisor calculator and care for my water as it advises. The calculator generates information based on the bio-load of full grown fish, and in my experience has been spot on.

Also, if you are adding schooling fish it would be best to add no fewer than 6 as loneliness might cause them undue stress.
Thanks, I guess I will buy 6 tetras then, I was just worried that was too much for a brand new tank. You let the tap water with conditioner sit out for 12-24 hours? Why is that?
 

bNissan

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@jscott There are two reasons that I know of to let water sit before putting it into your tank.
1. It allows the water to become room temperature which should be closer to your tank temp than your cold tap water.
2. It ensures that your water conditioner has been given enough time to clean up the water.
Letting it sit for 20-30 minutes would probably be fine, this is just what my dad taught me to do when I was little.
 

OnTheFly

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@jscott If you continue to do water tests at least a few times a week you will soon determine the best practices for YOUR tank. When to do a WC, how large it should be etc. Your stocking level will evolve over the next few months and your tank should stabilize. In addition to bio-load your local water very much matters too. We don't test for everything. Your tap water may have ten times more (or less) mineral content than some others posting this thread. In fact that is very likely true. In that regard my 15% WC might be plenty, and 50% barely enough for you. Mineral content aside, monitor your nitrate levels and your tank will give you a good idea what you should do to bring consistency to your nitrogen reading. And of course ammonia and nitrites as you add bio-load.

As far as stocking schedule.... If you don't use a QT tank, your community tank just became a QT tank. I would be inclined to get it over with and stock in perhaps three steps. Bringing in fish just one or two at a time over the course of months is a new opportunity to infect your tank, and potentially have to Med it repeatedly. I don't think I am being paranoid about this. Way too many dirty fish in most of our LFS, and the fish farms that supply them. Set up a temp QT tank in the future. All you really need to do is cycle a sponge filter in your main tank for a few weeks and you are always ready to set up a QT for future stockings. A simple Rubbermade tote is a lot better than no QT. I would suggest starting that process now is a good idea.
 
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jscott

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bNissan said:
@jscott There are two reasons that I know of to let water sit before putting it into your tank.
1. It allows the water to become room temperature which should be closer to your tank temp than your cold tap water.
2. It ensures that your water conditioner has been given enough time to clean up the water.
Letting it sit for 20-30 minutes would probably be fine, this is just what my dad taught me to do when I was little.
Yeah that makes sense, I thought maybe it had to do with pH or something.
 

Punkin

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jscott said:
I am adding schooling fish, and I hate adding two at a time, but everything I've read said to do that so you don't overwhelm the bioload... What do you suggest? 3 or 4? My ultimate goal is 8 Cardinals, 6 cories, 1 dwarf gourami, and maybe 6 cherry shrimp.
If it helps, I stocked my 20 gallon tank with 3 fish at a time with no problems. I also have tetras (black neon) and cories (albino). I also qt them in groups of 3 for 2 weeks. I have never had shrimp, but you may not have to qt them. And I believe they are a pretty low bioload.
 

bNissan

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jscott said:
Yeah that makes sense, I thought maybe it had to do with pH or something.
From what I understand it is an uphill battle to manipulate pH, and better left alone. If you buy fish from your LFS they are probably ok with your pH.
 

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I think it's a waste of time to let your water sit after being conditioned, especially in smaller tanks like yours. In my 20g, I treat the whole tank every time, and I have no problems whatsoever with this method. But it's a good point that it might just be my tap water. Everyone will have a different opinion on this one.

I'd add each species individually, but in their full school. That's how I stocked my 20g, and no problems at all. Different fish (honey gouramis, rasboras, loaches and amanos) but similar idea. Since each species takes up different parts of the tank, just add them by species, and let them get used to the tank as a group. I'd think this would lead to less problems long term.

If you ordered stability, I wouldn't worry too much about your cycle. I just make sure to add some when I add new fish, just to help in case. Hasn't failed me yet!
 

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jscott said:
Yeah that makes sense, I thought maybe it had to do with pH or something.
Sometimes the pH of tap water is high and will go lower when the water sits over night and/or is being aerated.
During winter time, some tap water has lots of micro bubbles that stick to everything, inc. fish.

Some people have copper in their warm water (pipes) which will kill shrimp and sensitive fish.
Know your water
 
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jscott

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Piaelliott said:
Sometimes the pH of tap water is high and will go lower when the water sits over night and/or is being aerated.
During winter time, some tap water has lots of micro bubbles that stick to everything, inc. fish.

Some people have copper in their warm water (pipes) which will kill shrimp and sensitive fish.
Know your water
W
Yep, I did that test today and after sitting out overnight, my tap pH went way down, which I've read is its "true" pH. No idea how to measure for copper...
 

Piaelliott

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jscott said:
W
Yep, I did that test today and after sitting out overnight, my tap pH went way down, which I've read is its "true" pH. No idea how to measure for copper...
I got a API copper test.
I killed my apistogrammas by getting warm water (copper) directly into the tank. My cold water doesn't have copper. All my other fish did well though.
 
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jscott

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Piaelliott said:
I got a API copper test.
I killed my apistogrammas by getting warm water (copper) directly into the tank. My cold water doesn't have copper. All my other fish did well though.
Wow, good to know, thank you.
 

JRS

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jscott said:
1. At the end of cycling a tank, using , without fish, I need to do a light vacuuming and water change, correct? What percentage water change?
After I fishless cycled my 5 gallon tank, I did about a 90% water change. Brought nitrates down below 5. That gave the fish very clean water to start and the BB is in the filter anyway.
 
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