Should i be doing 20% water changes twice a week for my goldfish?

I have five fancy goldfish in a 55 gallon tank. I have been reading mixed recomendations on how often I should be doing 20% water changes. The water in the tank is mostly clear, but is slightly hazy. You can only tell if you stand at least ten feet from the tank. I have several large HOB filters on it, which all have lots of beneficial bacteria in them. I have been doing ten gallon water changes every week in the tank, but should I be doing ten gallon water changes twice a week or just stick with that once a week?

 

Good morning TayJay76,

For Goldfish I recommend being on the high side of filtration. Having at least 10 x the tank volume for your Gallons Per Hour (GPH). So you're looking at, at least 550 gph. More filtration is better as long as the fish are not being blown around the tank by the current. I don't know all of the GPH's on the filters you have listed, but it appears to be enough. I'm sure others will chime in if I'm wrong.

Keep in mind that nothing beats freshwater for your fish. Personally I would increase your water change percentage to at least 30% or 16 to 20 gallons each week. Maybe even up to 25g's each week for your 55 gallon tank.

Goldfish are huge waste producers. Let's get more responses.

Ken

 

I'd like to hear more about the % of water changes as well. I have 40% weekly water changes stuck in my head, so that's what I'm doing right now.

 

I do two to three waterchanges per week totaling up to or over 50% of my tank. That's the best amount in my opinion. But I don't do it all at once.

 

I do 80% changes, all at once. The bigger the better.

 

I do 80% changes, all at once. The bigger the better.

I agree. I mean, I have everything out, right? Why not do it big.

And I have to say, I see 10% and 20% and such a lot, but I don't see the point of such small changes.

 

Yes but if you do small ones over the week then the fish have continuously fresher water in their tank. Do one great big change and they have a lot of freshwater but then it ages over the week. I have nothing against big changes though. I had to do big water changes on my larger tanks when I had them but I think a series of smaller water changes is better. Just my opinion though.

 

Yes but if you do small ones over the week then the fish have continuously fresher water in their tank. Do one great big change and they have a lot of freshwater but then it ages over the week.

How do you figure? if you only do a 20% change, then that means that 80% is still old. When you go to do the next 20% change, that 80% is even older, PLUS the 20% you changed is older. So now the next 20% is a mix of old and older water. So you have continuously old water.

With big changes, they have fresher water for longer.

 

Yes but if you do small ones over the week then the fish have continuously fresher water in their tank. Do one great big change and they have a lot of freshwater but then it ages over the week. I have nothing against big changes though. I had to do big water changes on my larger tanks when I had them but I think a series of smaller water changes is better. Just my opinion though.

Eh, I don't know. I don't think 20% new water and 80% old is all that great.

The point of changes is to get rid of nitrates, right? So if you have 80ppm nitrates and do a 20% change, assuming your tap water has 0, you still have 64ppm. If you do an 80% change you have 16ppm. Big difference.

 

As previously stated this is my personal opinion. No need to discuss it since it is of no use to the OP.

 

As previously stated this is my personal opinion. No need to discuss it since it is of no use to the OP.

Have you read the title of the thread?? This line of discussion is totally of use to the OP. It's what the whole thread is about....

 

As previously stated this is my personal opinion. No need to discuss it since it is of no use to the OP.

I apologize, I'm not meaning to come off as argumentative. Just trying to help the OP understand my line of thinking on the larger changes.

Cheers.

 

How big of a water change should you be doing? What kind of water change do you need to do to keep your nitrates down to acceptable levels (below 20ppm is necessary. below 10ppm is ideal)? Your goldfish are different from other members' goldfish. They are bigger than some, smaller than others. One might have a condition that changes his digestive system, making it less efficient (thus, more waste in the water). Thus, none of us can tell you how big your water changes should be without knowing about your water parameters.

Now, if you do as Jaysee does, and just change out most of the water every week, you don't need to worry about testing.

I agree that, if 80% all at once is good, that water changes spread out over the week that change out 80% of the old water (hint, it's not four 20% changes*) is better. This lessens the shock (which should already be fairly minimal, if you're changing the water on a regular basis) on the fish.

*When you do a 50% water change on day one, and then do another 50% water change on day two, the second water change is changing out half old water and half new (day-old) water. Thus, you've only changed out 75% of the water over those two days.
I'm bad at math, so I couldn't tell you how much water you'd need to change over 4 water changes in order to change 80% of the water, but I know it's not 20%.

 

I believe I have a good grasp of water changes and filtration.

In my opinion you should be doing one 20% water change per week.

Here is how and why.

I would aI'm to keep nitrates low with a 20% weekly water change and do not produce excessive current that your fish do not like.

My nitrates are 5ppm but at least aI'm for under 30ppm.

Having enough filtration means having enough biological capacity to break down the toxic ammonia in fish waste to toxic nitrite and then to less toxic nitrate. It should have a large surface area for bacteria to grow on. Not a high flow rate, which is something else.

Feed an amount that maintains your fish but does not add massively to the nitrate load which you are trying to keep down. After all, scientific experiments with Goldfish have shown they can maintain bodyweight on 2 flakes per day apparently (Practical Fishkeeping Magazine)!

You should test your water for nitrates regularly to get a picture of what is happening.

To change more than 20% per week would be more work and increased stress for the fish. It truly should not be necessary.

Regarding turnover, for Goldfish I would think turnover should be low. I have a turnover of 5 times the aquarium volume for my adult Clown Loaches which like current - and there is a real current in there! I would think that you need a much lower turnover for Goldfish.

I don't want to upset experienced people like Ken by suggesting something opposite but I'm sure he will enjoy the discussion and like me he wants to give the best advice.

If you cannot maintain low nitrates with a weekly 20% water change you may either have too many fish or are feeding too much.

Increasing water changes above 20% is the wrong way to go about it because it should not be necessary, causes it's own problems and points to problems elsewhere.

Also, increasing the flow rate does not necessarily increase the biological filtration.

Changing more water is more work for you. Both are far too much work and stress for the fish.

Food for thought?

 

I would aI'm for filtration that is good enough for you to keep nitrates low with a 20% weekly water change and does not produce excessive current that your fish do not like.

Here is one hitch in your idea.
Unless you're using ammonia-removing resin, filtration does not lower your nitrates. In a larger system (nature), nitrates get processed into nitrogen, but this happens largely in anaerobic conditions (which would be toxic in our small aquaria).
Filtration reduces ammonia into nitrite, and nitrite into nitrate, but the only thing that can remove nitrate from the water is actually pulling the water out.

My only other question is: You give excellent ideas for how to keep nitrogen production down, but you give no examples of what problems you believe are caused by doing water changes larger than 20%. What problems do you believe these to be?

 

Hi. Thanks for pointing out my paragraph. You're right, it's not well written and there is an element of confusion there.

What I mean is that we should aI'm for filtration which has the capacity to convert all the toxic ammonia produced by the fish into nitrate and then we should reduce this with a 20% water change. It doesn't have to be 20%, but most systems can be designed to run adequately on 20% so there's no need to do more and it's a "good rule of thumb".

I wasn't meaning to imply that we should necessarily employ filters that reduce our nitrates.

Our filters can be designed to lower nitrates as well, actually, as proven by myself and others so you are wrong to say that filtration cannot lower nitrates and that to do so would be toxic in aquaria. I do not obtain 5ppm with water changes alone I can assure you.

However, I was leaving that out of the equation for now for the sake of simplicity and addressing the question posed by the poster who doesn't have these filters.

I would like to point out that in my post I did give examples of reasons not to do more/larger water changes than necessary.

I mentioned that doing this would create more work - important in a multiple tank household like mine.

I also mentioned the stress this would cause to fish, meaning the mental (e.g. fright), physical (e.g. osmotic, temperature, water pressure etc.) and chemical (e.g. water mineral composition) disturbances associated with larger and more frequent water changes.

Naturally, I accept that we can change more water more frequently if we wish. I also accept that if we do this we can probably keep more fish or feed more food (within the capacity of the filter to deal with the wastes). If we do this we have to be prepared for the downsides of unnecessary increased work and disturbance to our fish.

A useful word I could have included, but didn't, is balance. It is all about achieving a balance between stocking, feeding, filtering and water changing -monitored by water- testing (especially for nitrate).

So, there is no clear right and wrong about water changes when operating well within the extremes. But if somebody asks for guidance:

My point is that I believe a water change of 20% should normally be acceptable.

I'm happy to discuss further.

 

Feed an amount that maintains your fish but does not add massively to the nitrate load which you are trying to keep down. After all, scientific experiments with Goldfish have shown they can maintain bodyweight on 2 flakes per day apparently (Practical Fishkeeping Magazine)!

This concept is a bit of a dangerous one to pass along. It does not take into account several important factors.

1: What size of goldfish were being experimented with?

2: Size of flakes vary a lot!

3: Feeding a goldfish only enough to maintain size, does not give them the nutrients required for growth. A stunted goldfish is not a healthy happy goldfish, and is far more likely to have a weakened immune system and succumb to disease.

4: Goldfish activity. Like all living organisms, a certain amount of food is consumed "just" to keep it (us included) alive. Varying degrees of activity increases the amount of nutrients required.

To change more than 20% per week would be more work and increased stress for the fish. It truly should not be necessary.

Changing 20% isn't any less stressful on fish than changing 50%, or even 80%
In fact offering lots of fresh clean water is less stressful on the fish in the long run, due to the added essential minerals found in the fresh water that all fish depend on.

Although the act of cleaning the tank may induce some stress to some fish, (so I've been told) I have never had my fish stress out due to tank cleanings, in fact mine have always seemed to rather enjoy it. Maybe it's what they get used to.

In any regard, I believe a short term stress provided by a tank cleaning is far more desirable than a long term stress provided by less than desireable water conditions.

Regarding turnover, for Goldfish I would think turnover should be low. I have a turnover of 5 times the aquarium volume for my adult Clown Loaches which like current - and there is a real current in there! I would think that you need a much lower turnover for Goldfish.

5x per hour would be acceptable if the filtration is provided by a canister filter. HOB filters, are best when they are capable of a 8 - 10 X's turn over rate. When it comes to goldfish, even more is better. There are tons of ways to decrease current if that is somebody's concern.

If you cannot maintain low nitrates you either have too many fish, are feeding too much or do not have enough biological filtration.

Or.... you're not changing out adequate amounts of water. I can not stress enough that water changes should not be performed solely for the purpose of removing "just enough" nitrates. Water changes provide so much more for your fish than just that. If nitrates is your sole purpose for doing water changes..... you are not doing your fish and other inhabitants any favors what so ever. Don't be scared of water changes! Water changes = good for your aquarium.

Increasing water changes above 20% is the wrong way to go about it because it should not be necessary, causes it's own problems and points to problems elsewhere.

What problems does it cause?

Changing more water is more work for you. Both are far too much work and stress for the fish.

Food for thought?

If it's buckets of water you are carrying, sure I'll agree it is more work. If you use a python type water changing system, there really isn't a huge amount of difference, just in the little amount of time it takes to suck up more water, and refill.

I already made my point regarding the stress on the fish so I won't repeat myself.

 

Again, not arguing, just giving my thoughts.

With a python it's no more work to change 90% than 10%, but I could DEFINITELY see how smaller changes would be very tempting with the bucket method. However it would be more work to do more frequent small changes because then I'd have to drag it out every few days instead of once a week. Not that that matters now since I'm doing daily changes with a cycle.

My fish never have shown sign of stress from water changes. The goldies love it, although the first week I had them, they got scared when their filter went off and would cluster in the corner under a plant. Now they try to get to the stuff flying through the vacuum and play in the new water coming in. No, it's not stressful seems like. It is just part of their normal routine and they seem to enjoy it.

Redshark, I'm not sure how you are using filtration to get lower nitrates. Could you explain your method?

 

toosie, thanks for your opinions.

snapper, my filtration achieves lower nitrates because anaerobic activity takes place within the bacterial floc reducing nitrate to nitrogen.

The tank in question has undergravel filtration and when it is set up in a certain way with a deep substrate it has aerobic areas where ammonia is reduced to nitrite and nitrate and anaerobic areas where nitrate is reduced to nitrogen.

This achieves nitrate of 5ppm for me when with a canister filter nitrate was 50ppm. I have large Clown Loaches and other fish and this method of filtration has proved a revelation, costing very little and being very suitable to the application. I'm sure it has been a factor in my fish achieving good health, size and age (17+).

 

Which brings us to a very important point.

Redshark's stock filtration system and (I'm assuming) tank size is different from Taylor's.
So what may be a good water change regimen for one may not apply to the other.

Let's stick to Taylor's set up in this thread.

Thanks

 

Wow guys thanks for all the insightful responses. I am taking these under deep consideration. I have had my goldfish for over one year now so they are all about 4 to 4 1/2 inches now. As said before they are in a 55 gallon aquarium. If you are wandering on how many or what filters are on that tank, they are listed on my profile. Please continue with the discussion. I'd love to hear your opinions, especially from people who have been with this hobby for far longer than I have.

 

they are all about 4 to 4 1/2 inches now. As said before they are in a 55 gallon aquarium. If you are wandering on how many or what filters are on that tank, they are listed on my profile

It would be wise to upgrade. It's great that you've gotten so far without it being a problem, but the fish are only going to get bigger. Your tank and fish would GREATLY benefit from at least 1 canister filter. The volume of media a canister can hold makes a significant difference in the capacity of the filtration system. A decent canister will hold all of the media from all of the filters that are currently running on the tank, and then some.

 

I simply can't do large water-changes, since it only comes out of the tap at one temperature: cold. And I keep tropical fish, which means it has to sit before I can add it, or I can't add much at all without stressing my fish with temperature shock, but I used to do infrequent larger water-changes. So with that, I thought I'd add my 2 cents to the discussion on small water-changes:
While obviously the smaller the water change the less toxins you take out, if you can do them more often (as in daily) they can help your water quite a bit more than if you try to wait until you find a good time to change out a lot. And if you miss a day, just take that much out plus the usual next day.
If you have large chunks of unoccupied time, congratulations, but I usually have to budget my time. For me, it takes it takes 15min. a day to do a 10% water change(and before somebody panics- I do larger water changes once every couple weeks, and I have live plants). Finding the time to change a larger portion a few times a week is a little harder for me.
If changing a little water more often works, it's fine, just keep an eye on your nitrates so they aren't slowly rising. If changing a lot of water occasionally works, fine, as long as your nitrates don't get too high between water-changes.
What matters is what it takes to keep the nitrates down, and what works for your lifestyle so that the water-changes happen.
And don't forget those gravel vacs, either- it's recommended to vacuum a 3rd of the gravel every week(in unplanted tanks- due to my plants, some areas aren't vacuumed, but some areas are). Of course, more gravel vacing may be required depending on how much they're producing, if they get ich and you use the heat treatment, etc.

 

It would be wise to upgrade. It's great that you've gotten so far without it being a problem, but the fish are only going to get bigger. Your tank and fish would GREATLY benefit from at least 1 canister filter. The volume of media a canister can hold makes a significant difference in the capacity of the filtration system. A decent canister will hold all of the media from all of the filters that are currently running on the tank, and then some.

I c and which canister filter would you recommend. I don't have that much to spend on one so I hope it doesn't cost to much.

 

for 5 goldfish in a 55

I would get 2 of these



or 1 of these



IME 2 smaller filters are better than 1 big one. The 2 filters will keep the tank cleaner.

I have a bunch of these and love them.

 

Awsome first one that is fifty bucks is sweet and cheap. Ill by two of them and still save money. Where can I find the filter media for these? Petsmart? That's my LFS.

 

they come with mechanical media. Some on ebay come with chemical and biological media as well. Not the one I linked to though. You can add any media you want - I think that biomax is the best.

 

Wow Gemstone, showers at your place must definitely be BRUTAL!!

 

Wow Gemstone, showers at your place must definitely be BRUTAL!!

Hahahaha, I was thinking the same thing!

 

Wow Gemstone, showers at your place must definitely be BRUTAL!!

Hahahaha, I was thinking the same thing!

I should explain: our tap water comes in through our pump, and goes through a general sediment water filter. Then it is split off: one line goes to another more thorough water filter with carbon, and comes out the tap for drinking water- this is what I put in my tanks.
The other line goes through a water softener and on-demand water-heater, and that line goes everywhere else(showers, washing machines, all other faucets, etc.). We have hot baths- hot water never runs out- but I don't use that stuff for fish.
a) higher sodium levels
b) lower beneficial mineral levels
c) that gunk dad used in the pipes(it claims to be non-toxic) isn't entirely out(it still shows up in the general sediment filter), and I'm not willing to bet my fish that stuffs ok. I think the carbon filters get most of it, but since it doesn't ionize I don't think the water-softener does... and I'm not desperate enough to find out.

 

Sounds very complicated, but I understand you are doing what you feel is best for your fish. I'm very relieved to find out you're not shivering too badly in the shower.

 

Thank-you for your concern. and yes the system is a bit complicated... But that's the price we pay for having all our water filtered to some degree, and having only some of it softened and heated. Trust me, I don't think my dad would survive having only cold showers- not because he couldn't stand the cold, but the wrath of 4 daughters and a wife could be dangerous ;D

 

poor guy

 

my dad? why? because he has 4 daughters and a wife(don't worry, he also has 3 sons), or because of what might happen if the showers were cold?
or were you referring to the OP? speaking of which, I think we are quite off topic, but I think most of the OP's questions have also already been answered.

 

Gemstone. I hate to break it to you, but you're babbling. hehehehehe,

 

Yes your dad

 

I'm babbling?? Oh.. Maybe I should have gone for 2 mugs of decaf instead.
I thought maybe my dad, but I didn't want to assume and then be wrong.

 

Hahahaha, Gemstone, you are priceless.