I concede I know nothing about keeping goldfish, but after months of reading this conference, I still have a fundamental question.... Why do the tanks need so darn much water changing. Other than evaporation and some vacuum clean-up losses, why do the tanks need such a high volume of new water.

Now before you jump down my throat, let me set up the parameters:
We are talking about, say a 55 gallon, bare bottom tank that contains an appropriate population of fancies... say 4, all healthy. Tank is cycled and has well-performing filters that turn over, say 1000 gph. Though bare-bottom, there are several living individually-potted plants flourishing under a nice balance of lights. A fine wall of air bubbles provides aeration and surface movement. All test readings are within acceptable parameters. Now, if that is the case, other than to replace minimal evaporation and vacuuming losses, why would I go in and disturb the fishes and their environment by doing some level of routine weekly water change??

I guess what I am getting at is the question of achieving a balanced and stable eco-environment in a tank. Is it really possible?
It seems to be the rare exception rather than the rule. In a way, tank operations seem to be more focused on the defensive approach, rather than on the achievment of the "balance."

Like I said, I am demonstrating my lack of GF knowledge, but it seems a reasonable question.

Oliver

I just assume that having something short of a pond and even most ponds cannot replicate real life. Therefore being a fancy goldfish, they are meant for show and not durability. Therefore it is important to make sure there is fresh water at all times. Just like replacing filters and media. a 10 gallon tank cannot sustain life on it's own. Not like a lake. Even with a lake, can you imagine how many diseased animals are out there that are non-domestic? A cat or a dog seems fine naturally if left out in the wild. Though none of us really know how many catch diseases and what types. That is why when domesticated, they must get vaccinations and see a vet. It is all upkeep. The same with changing water and these fish. I do 30 percent changes a week for my 30 gallon tank. Takes me 10 minutes. I change the filter every other week because I over feed and like to have fat fish.

The reason that GF tanks need so much water changing is because GF are waste-machines. To achieve a "balanced & stable eco-environment" in a GF tank, you'll need an insane amount of plants just to eat up the nitrate produced by the nitrifying bacteria in the filter.

With your parameters (55 gal tank, 4 fish, 1000 gph filtration, some plants) and "normal" feeding regime (say, as much as they can eat in 2 minutes twice a day), I'd say the nitrate will climb to alarming levels within a week or so, then you have to do a waterchange to cut down the nitrate. Whether you have 1000 gph or 10000 gph filtration, the nitrate levels will be the same.

So in short, it's almost impossible to achieve a "perfectly balanced eco-environment" for goldfish in a typical domestic gf setup, unless u got a huuuuge volume of water and more plants than you can think of.


Faust, when you say "change the filter", do you mean taking out the media and replacing them with new one? or is it rinsing them with tank water?

I meant the filter media. Like um....... The foam pads to my fluval filter.

You shouldn't put in new filter media, just rinse the old one, in tank water so you don't ruin the cycle!

Lots of things that the eye can't see are in there, and aren't necessarily things you're testing for in your water.

In the system you're talking about, without hooking up you water to some sort of elaborate hydroponics system, you'll never use up the nitrogen compounds the fish excrete.

Plants and bacteria in your biofilter (well, if you have a biofilter system and aren't tossing the sponges) both use up compounds dissolved in the water, which will eventually lower your pH, probably crashing it and killing off your fish pretty quickly. How long that takes is dependent on your water and lots of other factors.

As a natural method of competiting for resources, there is evidence that fish secrete a growth-inhibiting hormone. In a natural pond or river setting, this isn't a big deal for crucian carp when each fish may have hundreds of gallons. In an aquarium system, this will prevent your fish from growing and maturing properly. Plants won't remove that.

Plants will be using up other dissolved nutrients in smaller quantities, as will your fish, which won't be sustainable. By just topping off the tank, you don't remove anything dissolved in the water the plants and fish can't use, and the concentrations build up over time.

In theory you could get to a fairly balanced system artificially, but in practice that won't work in the long run for goldfish in the kind of tank you're talking about. You'd need a huge system as mentioned above.

In a fully planted tank with a few tropicals I can get away with just topping it off and only replacing water every few months. But the goldfish tanks can't handle it.

Carp are naturally riverine fish, and adapted to living in environments where the water is always new to them and passing through. Domestic goldfish, while they look different, still have similar metabolisms to their wild cousins, and do best with a lot of new water and oxygen.

Aiyah, that's the one thing you NEVER want to do unless the foam is really broken down (which takes yeaaaars). We strive to keep the nitrifying bacteria that lives in the the foam pads alive for as long as we can. If u throw away the pads, there goes the only reason why you use a filter in the first place.

No bacteria->nothing that converts ammonia to nitrite to nitrate->fish die. Better check that ammonia levels, mate.

I think the others have covered this fairly well - the nitrates at the end of the nitrogen cycle are the main concern - and most planted tanks are not up to the job of very many/large goldies. (some tropical tanks, lightly stocked may bea ble to be "balanced" more easily), but there is one aspect that was not covered.

http://www.kokosgoldfish.invisionzone.com/...?showtopic=7981

This is a discussion of growth hormones released in the waters by the fish. No only do many believe that this is correct, but there are other instances of other "physical growth inhibitors" that are present in a closed system.

I understand the process behind this, but when we are cleaning the filter media where do we clean it with the tank water? In a sink correct?

I clean it in a bucket with tank water...

Same here, I have to siphon into a Rubbermaid anyways so I just blast the stuff off with the water coming from the tank.

Are you guys serioius?! I am supposed to keep the foam pads in my canister? You have no idea how dirty the water gets. I get all kinds of brown sludge in there as well. So how often am I supposed to clean my fluval filter? Those foam pads turn from like. White to a dark red color. Ewwww, just thinking of what it all looks like when I clean it out. And after I do that, the water is nice and clear. Before it gets murky no matter how many water changes. Are you serious?

Yep. You want the pads to look dirty for the most part. Those are the goodies that make your tank thrive. Just give them a good rinse in tank water along with the filter itself if you wish.

Wow! Who would have ever thought. Okay I will try this. But I tend to overfeed. So this is normal? Brown sludge and all? That stuff ends up getting blown into the tank over time. So what do I do then? Should I go plant crazy to keep the water clear? Because I do 30% to 70% water changes weekly. Which may be a big no no, but it depends on how cloudy the water is. Man! Now I feel dumb. I just can't see how this all works. If the water is telling the truth.

The cloudiness of the water may indicate that the bacteria is trying to establish. It always clears up after a few days.

Remember: clean, sparkling water doesn't indicate good water parameters (which is the primary objective), it just means that your filter done a good job trapping all the solid waste (which is the secondary objective).

Btw Faust, can you describe to me what stuff u got in your canister & how do you go around cleaning your canister in detail, pls?

d-golem has a good question. BUt.... the filter pads should NOT look brown and "sludgey". That is mechanically trapped particles - particles that will all have to, eventually, break down into ammonia and be processed in the nitrogen cycle.

You will greatly enhance the efficiancy of your filter if you regularly clean these foam and filter pads. Because many filters depend on the filter foam or pads to be the main platform for your beneficial bacteria, you do NOT want to replace them regularly, and you do not want to rinse them in any water that may have chlorine or such in it - for you will harm the BB living there. Rinsing them will, however, greatly increase the gph of the filter - allowing more waste-laden water and oxygen to pass by the BB - and increasing the efficiancy of your cycle.

Anytime the filter cartridges or foam is plugged with gunk, squeeze them or rinse them or bang them clean in either used fish water or dechlorinated water. IT is also wise to build your platform for the BB in more than one place - in bioballs or ceramic cylindars or some such. These can be gently rinsed at each cannister cleaning - for they do not mechanically collect very much waste. A sponge or foam or floss will collect a lot of gunk - and needs regular maintainence.

Brown and gunky does not mean healthy - it just means used. Rinsing, squeezing, banging the gunk out is a good thing.

I'm not sure you addressed the basic question. I deliberately chose a larger tank as I felt "balance maintenance" would be unachievable in a small(er) tank. And, it seems to me that water doesn't "wear out," assuming the air stone and plants keep re-oxygenating it and the chemical parameters remain stable.
In a way, what I am asking is the possibility that relatively massive routine changes in a creature's environement (and 30% is massive) might do more harm than good to gf, which are so sensitive to stress.

Oliver

I guess I been doing this all wrong. I just read Daryl's response and it appears I have been going about this the wrong way. Here is the break down.

Bi Monthly:
Replace Carbon and Anti Nitrate media (I dunno what that anti nirate stuff is called. They are like crystals)
Monthly:
Change Foam pads
Every Other week:
I used tap water to rinse out filter canister

I do not change the bio particle stuff. I dunno what they are called. They are small and white and feel like stone or something.


So how often should I replace foam pads? This is new news to me and at the same time, sounds cheaper! :-D LOL Because I been spending a lot on pads and such. So it really doesn't require too much huh? No wonder why my tank keeps switching from crystal clear to cloudy as heck off and on. So in a 30gal tank with a fluval 205 filter, what would you recommend? I have another tank with a top fin filter and it appears those pads/filter media get clogged. Then the water doesn't flow regularly. I love the information you are all providing me with, and I thank you for your time to respond. I didn't want to hijack this thread, however I feel this is useful to the gentleman who posted this thread. Thank you all again for your input.

You have made some excellent points... I did forget about the consumption of trace nutrient elements in the water, although I would assume that a varied diet would cover that point. And, just as you mentioned, my prior experience with tropicals in a tank demonstrated how infrequently significant water exchanges were really needed.
Frankly, I would have thought that an avoidance of overfeeding, an absence of debris-catching "doo-dads" and gravel, plus careful vacuuming would have very significantly reduced the rate of nitrogen compound build up.
Please understand that I don't think the water must remain unchanged in perpetuity, but rather that the significant environmental changes to which the fish are subjected to via massive weekly water changes must be a real stress to their systems and a source of much of their physical vulnerability to diseases and attacks from "unexplained" sources.

Oliver

By the very nature of limiting the number of fish in the confined space of a tank, we are acknowledging and accepting growth limits. Genetic limitations not-withstanding, how in the world can someone say, "I want my fish to grow (to its potential), while simultaneously putting it in a restrictive container. Just a couple of days ago, the forum was bemoaning the condition of that single 7 1/2 inch fish in that small tank. What I'm getting at is that growth limitation is a given when one starts keeping fish, unless one is willing to minimize the number of fish and constantly expand the size of the tank for that one (or few) fish. I also wonder whether those hormones, being some sort of hydro-carbon compound , are not also consumed as part of the "cycle."

Oliver

When I can, I prefer to change a smaller amount daily, instead of a lot once or twice a week, but real life doesn't allow that very often (not when changing my big tank takes over 4 hours every 5 days or so). I think the fish respond better (so yes, I play favorites if I can only do one tank a day). Someday I'd like to set up a trickle system that continually changes a small amount of water, but I don't have the resources. All the things you mentioned do keep nitrate build-up to a minimum, but don't keep it low enough for my tastes.

For now, when I do large water changes and it is possible I usually set the refill to go verrrrrrry slowly, so the fish are not subjected to a sudden change. Sometimes slow enough that refilling the 30 gallon tank could take 2 hours. And just watch TV or work on a laptop while I wait. It is a little over-the-top, but if I can work on other things the extra time doesn't matter much to me. It also takes care of some of the changes my water goes through as is gases off and mellows out and makes any small temperature differences easy for the fish to handle.

I've seen arguments for and against large water changes, and as long as your fish aren't exhibiting a negative reaction, I don't think it is "bad" to do either. People set up tubs and move move fish into entirely new water every few days with good results especially in green water systems, some people swear that it is better for the fish to keep them in mellowed water that has matured by only being gradually changed.

The longer you go without a water change, the more the new water will differ from what they have. And the more of a shock that large change will be. With small fish, the nitrates don't build up so badly, and you can go a little longer. But once their bodies are over 5 inches long, It is pretty easy to have nitrates climb to over 100 in a week or two. It isn't immediately deadly like ammonia, nor as quick to kill as nitrite, but in my opinion it compromises their immune systems more than any response to the water changes.

If you get a lot of cloudiness, you can improve your mechanical filtration to trap more particles. (the milky white cloudiness is usually a bacterial bloom caused by an ammonia spike, other cloudiness is debris your filter isn't trapping). Using chemicals to remove ammonia and nitrate can also keep your tank in good shape, and maybe reduce water changes, but it will be much, much more expensive. Which the manufacturer of those products would obviously prefer.

Well in a general thinking goldfish are messy even if you have good filtration and large tanks for them, they are swimming in here pee. water changes are needed to keep the nitrates low and keep things balanced.

Hi Mr Black

when you talk about keeping the chemical parameters stable, no amount of oxygenation will reduce the amount of organic waste that is in your tank. the amount of plants you would need to keep to process the amount of waste just one or two goldies would pretty much cover the whole area of your tank, not to mention that your goldies would eventually eat these plants and the dead/eaten fronds of your plants will also contribute to increasing the level of organic waste. The reason why we want to keep "nitrates" low, is not necessarily just cause we want the nitrates out of our system, but they're indicative of the compounded level of organic waste/breadkdown products. The only way to keep down the levels of 'nitrates' and to keep the chemical parameters 'stable' is to do regular waterchanges. These waterchanges can be less stressful for a fish if the fresh water is isotonic/isothermic and pH matched to the tank water. At the end of the day, I personally believe that the stress that the fish undergoes from waterchanges is much less than the stress from chronic exposure to organic waste which can suppress the fish's immune system.

My 30 gallon has been cycled for about 3 months. Every Monday I do a 30% water change in it, and a 20% in my 10 gallon tropical. I add Prime, rinse the filters out in the tank water before I discard it, and my water params stay fine. The entire process for both tanks takes about 30 minutes tops, and I also vacuum the bottom as I tend toward overfeeding a little bit. I never see poo or old food laying around and the water stays nice and clear.

Is the anti nitrate thingy called NitraZorb? Anyway, personally, I think both of them are not needed in a filtration system because their functions are peripheral only. Carbon is mainly used to clear any medications in the tank and also for making the water crystal clear. IMO the cost of constantly replacing the carbon pads outweigh its usefulness. I haven't had any experience with NitraZorb so can't really comment on that, however there doesn't seem to be many hobbyists which use them other than cases of emergency or such.


Now you know that the foam pads must never be changed. If it gets clogged, just squeeze it in tank/dechlor water to clean it. A sturdy foam pad will last you years.


Never, EVER, let any of the filter media you have (bio-balls, ceramic rings, foam pads, carbon, etc etc) touch tap water. If you want to clean only the filter casing, then tap water is fine.



Exactly what I feel . U just cannot compare goldfish & tropical. A goldfish will produce (generally speaking) 100 times more waste then a tropical of comparable size. To achieve a "balanced eco-environment" in a domestic gf setup is just almost impossible.

My filter pads have carbon, but I don't replace them. Even when the carbon has outlived its usefulness, its still a good media for some BB to attach themselves. And I do like the crystal clearnesss that the carbon filled fiber pads give the water.

I only clean the tropical tank at the same time as the goldie tank because it has gravel, and I tend to overfeed a little bit.

Thank you so much for the time to help educate me on this matter. I feel quite excited to attempt this and the fact that I shall be saving more money is always a plus! Now I can work on getting bigger tanks! LOL I envy your knoweldge.

It's all part of the learning curve, mate

Oh one more thing. If I am not replacing foam pads in the filter or the media, then why even bother with a filter? Just a quick thought. If good backteria is already in the tank as it is established. Something isn't really clicking here. I guess I don't understand. Do you all see what I am saying? Is the bad bacteria going into anything? Does it get eaten by good bacteria and it just works better in the filter for some reason? I guess I just am confused now.

Hi Faust

The good bacteria is in the filter media while there is some of the good bacteria in the tank it is very little almost not important that is how much is actually in a tank ie. gravel or stones. We use a filter to remove the impurities in the water (not sure if that is the appropriate word) but they help remove waste in the water such as poop and left over food. It is also a place where you can colonize your good bacteria to eat the ammonia, nitrite and turn it into nitrate. (refer to nitrogen cycle if unsure about ammonia to nitrate) By replacing the filter pads you are removing a colony of beneficial bacteria which is what you are trying to colonize. If you left the sponges in then you can establish a proper established cycle (reading 0 ammonia and nitrite and anything above 0 for nitrate)

To your question about filters they are used in tanks as the amount of water is so tiny compared to the wild where there are 1000's and 1000's of gallons of water in a lake which is constantly circulating providing oxygen and it's own filtration system which is based on the natural algaes, plants, and the bottom feeders such as freshwater shrimp. That is a true ecosystem where the balance is untouched and is a never ending cycle. (well at least until human contact) That is actually why a large reef aquarium with corals, fish and sea hermit crabs etc and enough filtration is alot less work as it is the closest thing to an ecosystem which can be established by man. All you need to do is a water change once a week and top up when the water evaporates in a marine tank.

Hope this clears some things up

In supplement to Dan's answer, the filter does move the water around so its better oxygenated, but it also removes the physical pieces of dirt, dust, and waste from the water the fish is swimming in. Filters are much more about *physical filtration*, getting the grime away from the fish - they are not about getting out bad bacteria. If there's bad bacteria, that's typically up to your fish's immune system and, if needed, medicines, to take care of.

Faust, while the "knee-jerk" assumption of the function of a filter is to remove waste (poo, debris, etc), the most important job of a filter is to let water pass through the filter media where beneficial bacteria lives. If there's no device to make the water pass through the media, then the bacteria got nothing to eat, then they die.

So the chronological order is this:

Goldfish produces waste (ammonia) ---> toxic water with ammonia got sucked into the filter ---> flows pass thru the filter media ---> beneficial bacteria in the media converts ammonia to nitrite, nitrite to nitrate ---> less toxic water containing only nitrate is expelled back into the tank.

So, to (sorry) correct dan & fredct, the main job of a filter is not so much the physical filtration, but is to convert the toxic ammonia produced by our goldfish to the much less toxic nitrate.

Clear as daylight! Thanks so much for that answer. Now that makes sense.

I understand what you saying and not going to start a debate but isn't it true that is not necessarily true as if you have a green water set up then you do not need filtration as your filtration system is infact the algae it self all you need is enough aeration

Um...is this a question? Sorry mate, can't really quite grasp what you're trying to say here

just to follow up on this hijack topic... like Riz, Dan, I'm sorry, I don't quite understand what you're getting at? "isn't it true it's not necessarily true" too many double negatives, it's difficult to make sense in exactly what you're saying. I'm not trying to pick on your grammar, but what you're typing, to me, is uninterpretable.

I also wanted to add my 2 cents about biological filtration that hasn't seemed to been mentioned in this thread that may make it easier to understand....

1. the 'good bacteria' needs a surface on which to grow, it's not really free-floating in an establised tank. -that's why your filter is a sponge/bioballs/ceramic noodles, it gives the largest surface area for the minimum space (similar to our lungs for oxygen transfer). That is also why you want to clean your filter of all the 'gunk' (mulm) that gets caught up, to keep the surface areas free for the bacteria to grow on. yes there will be some residual 'good bacteria' when you take out the sponge, but not enough to process the waste that is produced by your goldies, -To continue with the comparison of biological filtration to oxygen transfer in the lung, it's like removing our lungs, -yes some oxygen will get transferred across some of our membranes, but there will not be enough O2 for us to survive.

2. bacteria in general are in 'constant competition' with each other, so no, the 'good' bacteria doesn't actually eat the 'bad' bacteria, but if you give them the right environment (ie a nice big surface area that has a constant supply of 'food' (that being ammonia and nitrites)) in which to live you are tipping the odds in favour of colonising 'good' bacteria which can in turn outcompete with 'bad' bacteria.

fair enough mads and Riz know i don't what i typed lol i agree to many trues cancel everything out wow that was bad grammer

Hey Oliver - just wanted to add one thing as this topic seems to have gone off on a few tangents.
Everyone has mentioned the build up of nitrates and organic waste in the tank which regular water changes will dilute. But the other reason w/c's are very important is that, without them, the rise of nitrate (nitric acid) will eventually use up all of the carbonates in the 'unchanged' water causing the PH to plunge into acidity. This is called PH crash which you may have read about in various topics on the board. GFish hate drops in PH and a crash will usually kill them. By regularly adding new water you are not only removing organic waste but also providing a constant supply of well buffered water to maintain a healthy PH.

OK... that makes sense. Just a few moments ago I was recalling my pool/pond pH reading I took back in September. It was 7.0.
Since the pool is full of and refilled by rainwater (I don't think we have much acid rain here and the pool is painted concrete), I suspect that neutral reading will be a given. I do wonder, however, if tree leaves that have accumulated in the pool or on the porous pool cover will generate some sort of acid from the decomposing tannin material.

Oliver