Water changes

[Dr. P]

Just curious as to what kinda maintanence schedule you all have? How often and how much water do you change?

Cheers.

[Tristan]

100% every day
No only joking I do maintenance when I do my other tanks which is about every fith day. I do a 30% water change on all my tanks. If ia have a hectic social week I might leave it a week, but that is rare as i have no friends

[Dr. P]

LOL!! Pretty much the same as me (but I have friends )

Be interesting to see how the rest of the members do it.

[DasArab]

(but I have friends )

[McEve]

I usually change 20% once a week, but now that I have frys in the tank, I try to do a 10% every other day instead.

I keep thinking of an autamatic water changing system, but the ideas I've had so far is just to dangerous - involving lots of water running down to the apartment below

Wouldn't it be great to have though

[Robert Hadath]

I change the water in my breeding tank 30% once every 4 to 6 months when I clean the sponge filters. In the interim I simply top the water levels up when they get too low. In my fry tank I change the water about 10% every 2 -3 months.

I know this is allot less than most people like to do, but if it aint broke...don't fix it is my motto.

[DasArab]

Hey man im not dissing you or anything, Do you test your water for Nitrates? And if so whats the readings?

[Robert Hadath]

You can Dis me all you want. My fish are happy, eating growing and breeding. The adults have thrived this way for over 2 years.

Of course the fact that There are only 15 fish in a 70 gallon planted overfiltered tank could be beneficial.

I have always been a strong believer in letting nature do its job. If you create a balanced ecosystem there should be no need for such frequent water changes.

I keep discus as well. They do not get water changes more than 20% every two months. They are huge and healthy.

Keep fish volume low and do not overfeed. I find I am more likely to lose fish due to frequent water changes, especially the young ones. These fish do not seem to like changes in their water parameters. The only time I hada fatality was in my fry tank after a water change. Well that and the time I accidentally squished one with the net, but that does not count.

My opinion.

Robert

[Adam]

Hi Robert,

Congratulations on your breeding success with the zebras and welcome to the forum.

That's an interesting approach you have to water changes and it clearly works for you. I'm afraid that I change water in my tanks on a weekly basis and sometimes even twice weekly the amount varies between 20% to 60%. Unlike you I have broken all the stocking ratio rules at least twice over. I can understand the science behind your thinking, theoretically you could run a tank without any filteration providing the stocking ratio is extremely low and the tank is heavely planted. One of the LFS I visit occasionally has a setup like this and it seems to be ok.

As we all know the end product of the nitrogen cycle is nitrate, you would automatically think that plants would be able to utilise this. If you are at all green fingured you will know that most fertilisers contain a form of nitrate amongst other things. However aquarium plants are not able to use the form of nitrate that is the end product of the nitrogen cycle. What happens is that the nitrate level increases until it reaches a toxic level for the inhabitants of the tank, studies have shown that this could be as high as 1000ppm. If your stocking levels are sufficiently low it could take several months for the toxicity of nitrate to reach a lethal level. Just out of interest it would be interesting to see what level your nitrate has reached prior to a water change.

The most practical way to control the nitrate concentration in a tank is to reduce it through regular water changes. Another method is to run a nitrate filter, this is a fairly complex and troublesome form of filtration.
Conventional forms of filteration rely on the cultivation of aerobic bacteria to aid in the nitrification process. A nitrate filter however will be colonised by anaerobic bacteria, this is achieved by starving the filter of oxygen through a greatly reduced flow rate, as little as 1gph. Under these oxygen deprived conditions only anaerobic bacteria will be able to populate the filter, in order for these bacteria to perform their biological functions they are forced to metabolize nitrate. In addition this type of filter requires regular feeding with an organic compound. Years ago I use to run a nitrate filter but it required constant supervision and was plagued by problems, my bacteria kept on dying off. Commercial units are now available that may be more efficient and require less maintenance. Denitrification filteration is more commonly used within the marine side of the hobby as many invertebrates are extremely susceptible to nitrate poisoning.

Another reason why regular water changes should be undertaken is that fish do not acquire all of thier nutritional requirements from what they ingest, a proportion of nutrients is absorbed directly from the water. Therefore the older the water in the aquarium the lower the concentration of these nutrients.

If you do test for nitrate and find the level to be within normal parameters this is likely to have been caused by denitrifying bacteria colonising the substrate in your aquarium. This can occur in an aquarium that is heavily planted or has a deep layer of substrate.

My oppinion in support of regular waterchanges.


Adam

[McEve]

Very well said Adam. I know it is possible to set up a self maintaining system, but I think I'll keep changing the water as I have before

Selfmaintaing can look like this one

I read somewhere that fish can develop quite som tolerance to Nitrates, and seem quite happy in water with rather high concentration. But the result being that they don't make the transition over to a clean enviroment.

I'll see if I can find out where I read it and provide a link, even though that doesn't prove this at all - I'm not sure it's true.

Robert Hadath: do you measure your water values? What kind of filtration system do you have?

[Cascudo]

I do 20% water change every two weeks.

I have my doubts on Robert's approach, especially because you only refill for a longer period, in this way increasing the concentration of minerals, as only the water evaporates. (This way the Dead Sea is created, I admit that they don't do water changes over there every 4 to 6 months either)
Also I have my doubts if you can really create a closed ecosystem in a 70 gallon tank, comparing to natural waters, this is a really small volume.

But if it works for you. What can I say?

[Tristan]

I am interested in the discussions above as it is always nice to see other peoples approach to fishkeeping. I must admit that i have left discus in a tank without any water changes for a month only to find that they had laid eggs, although I am not sure that i would do it again.

I know that a lot of advice given in the fishkeeping industry is peddled through the large corporations in order to sell the aquarist more/ different products. One breeder i know does 25% water change every 4 days with untreated tap water and his fish are breeding like crazy. He recons that de-chlorination liquids are a waste of money and that in an aquarium the act of pouring the water into a tank will release most of the chlorine. Any one have any thoughts on this.

Again not something that i would risk doing especially as chloramines and now flourine are being added locally. BTW does anyone know of any experiments that have been done with tropical fish and flourine over long periods of time. My local water authority didn;t have a clue what i was on about when i contacted them regarding the situation.

Tristan

[Robert Hadath]

Thanks for the detailed report. I did not know that plants could not use the end product of the nitrogen cycle in the aquarium. I guess that I am just lucky that my tank volume is so high and my fish population so low. I will have to buy a test kit and see what it says.

I guess that my water changes are more important than I realized. It could be that the amount I change is higher. When I finally do take the water out for the water change I take it from the tank while it has been evaporated down to aprox. 7/8 of the full volume. This would mean that I am taking out concentrated water and diluting even further with the fresh water I add. MAybe two years is not a big enough window. Perhaps it is slowly getting worse and worse and I have just not reached a critical concentration level yet. Well, I will not wait for that to happen. I will start doing water changes at least once a month now. I guess in nature there is a constant supply of fresh water being added to the system via rainfall and the system is dealing with an even greater volume of water compared to fish poplulation.

I will not take chances with my fish. The one concern I have was the mention that fish can adjust to these higher concentrations and then die when moved to fresher water. How should make the transition to more water changes?

Thanks for the heads up.

Robert

[DasArab]

Dont know if that was just a typo but plants do use up NitrAtes, the end product of the nytification cycle. NitrAtes are a basic form of Fertalizer, thats why people recommend useing tank wtae rto fertalize house plants.

As for increaseing your water changes I would go from doing them evrey 4 months to every month, as you have said. Just do the changes as youve done them before except more often. I would do that for 4 months or so then start doing them every 3 weeks or so. As you say you do have a big tank with small inhabitants. So water chnages every 3 weeks should be ok, IMO. As long as your NitrAtes dont go about 40ppm you should be ok.

[Adam]

Yes and no Ewee. The form of nitrate that most plants use is Ammonium NO4+, the nitrate that is the end product of the nitrification process is Ammonia NO3-. The vast majority of higher plants that are cultivated in fresh water aquaria are unable to utilise NO3-, however algae is able to thrive on it. This is why aquariums that have a high nitrate reading are more prone to algal blooms.

If you were to cultivate an aquarium full of algae especially the blue green variety that would definately keep your nitrates in check, mind you it wouldn't look too good.