Jump to content

Water Changes


Scienceman

Recommended Posts

Yesterday at a trade display for a scientific conference in Sydney, I spoke with a rep from a US aquatic supply company (some researchers breed zebra fish to do developmental biology studies on developing eggs / embryos) - www.aquaticeco.com

He told me that for most aquariums the need for regular water changes was a myth perpetuated by companies selling water conditioning chemicals and that he and others he knew kept both fresh and salt water tanks without regular water changes (only a couple of times a year). He only added RO (reverse osmosis) water to top up evaporation.

He said that plants would take care of most of the nitrates and carbon filters would remove most of the other trace nasties which would accumulate.

Of course with cichlids it is difficult to get plants to grow in a tank (I have managed 2 well chewed but living anubias) so we would still need to remove nitrates with water changes but it got me thinking.

If he is right, it would make keeping a salt water tank much easier and cheaper.

Link to comment
Share on other sites

It may not help but my fish sure seem to be happier with a small weekly water change than when I go away and they miss out.

I agree that if the tanks are well planted then nitrates are reduced and that regularly changed carbon can be used to reduce the buildup of other chemicals.

I'm dubious about the idea that water changes are a myth perpetrated by the water conditioning chemical companies for several reasons. It's actually quite easy to measure the chlorine and chloramines in the water and it's pretty cheap. That said, I do know people in Sydney who just put the water in a tub for a week and then put it in the tank with no chemicals and they seem to have healthy looking fish.

Personally I kind of like the routine of changing a bit of water once a week and I'd not be too comfortable not doing it.

I also know people who just top up and never change water (hi hph smile.gif ).

Link to comment
Share on other sites

I went to a NSW Cichlid society meeting last year where Anthony gave a fascinating talk about the use of plenums in fresh water setups. From memory he said he went a year without a water change - just top ups after evaporation. The fish were all fine although the colour of the water was a bit dodgy.

Foai

Link to comment
Share on other sites

If someone can put a tank together, and have JUST the right balance between the waste produced by fish numbers, and the amount of plants required to make use of ALL their waste products, then I expect the need for water changes could be reduced. Not eliminated

With a fully stocked Planted tank (and by this I mean a planted tank that also happens to have a few fish, not a fish tank with a few plants), the need for water changes may be reduced. However water changes in this case may not take out toxins in the water that perhaps plants don’t need, but the new water may also bring in trace elements that the plants require and that may not be present in the fertiliser.

Short of having some sort of PhD how will an aquarist KNOW they have stuck this balance. Just because things look okay to our eye, we are not living in the water that our fish are defecating and urinating in.

A marine tank is a whole other kettle of fish (no pun intended), and you will not get this balance between waste produced being consumed by the tank’s algae.

You could limit your water changes by selective resins to remove phosphates and so on, and a plenum system will also go a long way to improving your water conditions, as will other forms of nitrate reduction. But at the end of the day, a plenum needs to be set up just right (and it is very demanding), and the moneys you are spending on special resins, would be moneys other wise spent on salt water. What happens if your late changing your resins for a couple of days?

Anyone who thinks they can get by without doing water changes is just kidding themselves, and if you think your fish are okay, and there maybe some truth in this (if you really know what you are doing), you will still be reducing your tank’s Life Buffer Capacity if you skip or eliminate your water changes – and this is not a good thing. One day you’ll come home and there will be a disaster and you’ll say, “gee – they were okay yesterday, I wonder what happened”…or some other problem will occur, which will tip the increasingly precarious balance that you have unknowingly been maintaining, due to lack of water changes.

In short - a fish tank is a commitment to labour, if you talk yourself into believing you no longer need to do water changes, be aware you have rationalised this due to a basic and intrinsic laziness.

Almost all literature will inform you of the need to do regular water changes. This has been happening for years. And though our gadgets and knowledge have improved over the years - KISS - water changes take care of a lot of evils, and increase your tank's Life Buffer Capacity. If you subscribe to some sort of conspiracy theory about the need for water changes being propaganda put out by companies that sell water ager products, then you should go back to watching the X-Files.

Craig

Link to comment
Share on other sites

in regard to the marine setup(where most innovation comes from)if you run an anaerobic filter or plenum it is theoretically possible to just do freshwater top ups,its my understanding that this has come about to tap the huge us market that would like a reef tank but found the maintainance too difficult,hence companies like laguna brought out all in one tanks ,simply add salt water and fish plug it in and away you go,this was all very well IF you love damselfish and IF you keep adding trace elements , any more difficult animals i.e. invertibrates and butterfly fish etc and a huge array of chemicals trace elements and colloid removers are necessary,as well as the animals using up these additives the built in protein skimmer stripped them out

all this can be avoided with the use of a decent cannister filter or sump and fortnightly 25% water changes using clean natural seawater but for some reason people find this hard to do so all the nemos etc died and the tank finds its way into the classifieds or ebay

in conclusion yes you can keep fish with no water changes if you invest in a bit of equipment and have unlimited resources to tip additives into the tank,myself i prefer the old fashioned way and my nemos spawned

Link to comment
Share on other sites

In the original post in this thread, Scienceman quoted the guy as saying he only does a couple of water changes per year - this is roughly what Craig has explained - you can lengthen the frequecy via certian management methods, but they cannot be elliminated totally.

I use simple coil denitrators & have found them to be a help - even my most heavily stocked tank only gets approx 20ppm nitrate after 2 weeks whereas it used to get that in a week. Now I've added to the "life buffer" by using the coils, but I've also taken away via the longer waterchange intervals so in my mind I'm roughly at the same place, with less work. If I had more sensitive species, I'd use denitrators AND weekly changes - but 'sif CA's are sensitive.

Link to comment
Share on other sites

When ever these "systems not needing water changes" debates are had, people tend to concentrate on the chemicals that are easily measured, like nitrates, pH, etc.

What tends to be forgotten, are the chemicals you can't see and are not easy to measure. These include organics, hormones, growth inhibitors, etc most of which are released by the fish or plants themselves. While these chemicals are not highly toxic and therefore don't kill your fish, they have been shown to be detrimental to growth and probably interfer with health in other ways.

How are you going to prevent these chemicals from building up in your tank? Some no doubt are broken down by bacterial processes, but many aren't. Carbon may remove some of them, but you would have to change it regularly to maintain its effectiveness. Why bother when water changes are much cheaper and more effective. Probably the most cost effective maintenance you can do for your tank.

Cheers

Brett

Link to comment
Share on other sites

Personally I reckon that bloke was a rep for a carbon company... woot.gif I haven't bought carbon in a while but the amount you would need to change every month (???) would be much more expensive than a dose of prime and some tap water IMO. And your front garden will love you for fish waste water (even my alkaline waters seem to get our roses going well!)

Having said that, I do believe plants, plenums, denitrator coils can reduce the frequency of water changes required, but not eliminate the need for them completely. (Reasons well documented above)

Link to comment
Share on other sites

Interesting that people talk about plants reducing the need for water changes. I find a planted tank thrives with a water change - which obviously means I am crap at fertilising planted tanks and missing some element that is used up and replaced. blush.gif

Steve

Link to comment
Share on other sites

When ever these "systems not needing water changes" debates are had, people tend to concentrate on the chemicals that are easily measured, like nitrates, pH, etc.

What tends to be forgotten, are the chemicals you can't see and are not easy to measure. These include organics, hormones, growth inhibitors, etc most of which are released by the fish or plants themselves. While these chemicals are not highly toxic and therefore don't kill your fish, they have been shown to be detrimental to growth and probably interfer with health in other ways.

How are you going to prevent these chemicals from building up in your tank? Some no doubt are broken down by bacterial processes, but many aren't. Carbon may remove some of them, but you would have to change it regularly to maintain its effectiveness. Why bother when water changes are much cheaper and more effective. Probably the most cost effective maintenance you can do for your tank.

Cheers

Brett

Spot on Brett.

Link to comment
Share on other sites

I use a plant, hornwort, that grows well in hard water with minimal light. I have reduced my water changes condsiderably with no ill effects - fish thriving and breeding.

David,

Have you seen a change or have you tested your water?

All,

Alot of marine tanks use a refugium on a reverse lighting cycle. This supposedly reduces the Ph drop during the night. Can we use a plant such as hornwort to acheive similar results?

Troy.

P.S. FWIW, I do believe water changes are necessary. In the wild, water changes are accomplished via the natural flow of water, i.e., tides, river flows, stream flows, etc. In other words, fresh water is constantly added to the local "system". In our tanks, the same water is recycled over & over & over.

Link to comment
Share on other sites

I dont know whether or not the chemicals in my tank change, but I find that a water change will increase the chance of my fish spawning. Maybe its worth a try to take out the same water and replace in the tank and see if this still encourages spawning.

Adam

Link to comment
Share on other sites

Adam you'll find that is often the result of cool fresh water. It supposedly mimics the melting of the icecaps in spring (and we all know what animals love to do in spring smile.gif )

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...