Mathematical approach to waterchanges

[pastry]

Good grief this thing got crazy... but I still would like to encourage pascal to do it. If anything, for my own greed, I'd love to see some sort of benchmark/"round about target" where the positive impact of WC's drops off with "X" amount effort of new water you put into your discus tank. For example, is it worth changing 100% 10x a day or will you really not get much of an impact on growing your discus after doing 2 100% WCs

...not that I'll get better at WC's but still would love to know or see what someone comes up with :P

Sorry if I used any terminology jargon wrong for anyone

Pascal, love to see what you do but please explain in terms that a rock (me) could understand once done! Thanks!

[pascal]

Good grief this thing got crazy... but I still would like to encourage pascal to do it. If anything, for my own greed, I'd love to see some sort of benchmark/"round about target" where the positive impact of WC's drops off with "X" amount effort of new water you put into your discus tank. For example, is it worth changing 100% 10x a day or will you really not get much of an impact on growing your discus after doing 2 100% WCs

...not that I'll get better at WC's but still would love to know or see what someone comes up with :P

Sorry if I used any terminology jargon wrong for anyone

Pascal, love to see what you do but please explain in terms that a rock (me) could understand once done! Thanks!

Pastry,

If you are doubling the WC frequency by 2 (that means dividing the period "p" between two WC's by 2), nitrate concentration will be divided by 2. In our example some pages ago, we calculated that with the set up, we needed 40% WC daily to achieve a nitrate concentration of 5 mg/l. If I apply twice a WC of 40% a day, nitrate concentration will be at 2,5 mg/l. At four WC's of 40%, it will at 1,25 mg/l etc...

You feel that from a moment, there will be a level of no concern. Increasing WC's to that level doesn't contribute significantly to the nitrate concentration. Eight times 40% a day would give 0,6 mg/l. What's the difference between 1,25 and 0,6 mg/l , almost nothing.

But there is more than nitrates alone. Read the interesting remark from Ricardo a few replies ago. He saw a difference between 100% per day and 50% every other day. I can hardly believe that in a normal stocked tank this is only due to the nitrate concentration. Could be, but I suspect other factors having an influence. Even at 50% every other day, nitrate concentration must still be very low.

[pascal]

It is fair to say that this thread is of two minds, those that agree that this theory may work, and those that do not. However, there is a difference with discussing a matter, and simply shooting someone down and making them feel unwelcomed.

OP, I stated very early on that I believe this to possibly work in theory, but would probably not work in a real life scenario. There are many contributing factors to raising out discus, and food is a large part of that. How would you determine the different levels of waste each would produce, especially for those that feed home made food that would be difficult to completely break down and assess their potential contributing value?

I enjoy your presentation, more so because of the way you present it. As you have seen, there is a far simpler way that others have come across a long time ago and it is a vetted practice, large water changes. In theory, this is what your proposed process may actually lead to, more water changes, but being that we are only talking about this as a theory, it is difficult to put it in to practice.

Here is a real world example from a few years back:

I had 5 discus in a 55g tank being QT'd. These 5 discus were getting BH/flakes/pellets daily, and fed about 5 times a day. 100% WC's a day. After a while, I started slacking on my WC's. The 100% WC's turned in to 50 WC's and daily turned in to every other day. Well, my discus definitely started showing me signs of stress. They got small blisters, became more skittish, and also were darker more than previously. I got them back on track with their daily WC's and they returned to normal.

Now, we can definitely see how there is a correlation between Feeding/WC's and discus healthy in this very small microcosmic example, but the truth is simply that I have done it many ways, and the best way to raise discus is simply to do large water changes. Can you grow out discus with 1 WC per week? Yes actually, you can, but chances are that they won't be healthy, or possibly will not remain healthy for a long time. We are here (maybe not all of us) to raise some really large healthy discus, in order to best do this, is to use the K.I.S.S. method, and it just turns out to be that the best and easiest method is to do large WC's. That is possibly why you are getting flack for your proposed example.

I encourage you to try it, not so that I can gloat at you if it happens to fail, but because if anyone has a chance of making it work, it can possibly be you. We have sections here on this forum that can help us track your progress, and you can even buy a membership here on the forum and start your own blog.

I still remain interested in your proposed idea, but just know, it will not mean much around here until it is being practiced and shows promise.

Rickztahone,

Thanks for your intrest. Can you explain me what is the K.I.S.S. method?

[nc0gnet0]

Rickztahone,

Thanks for your intrest. Can you explain me what is the K.I.S.S. method?

K.I.S.S = Keep It Simple Stupid

FWIW, the principal of dynamic equilibrium has already been discussed in much simpler terms here:

http://forum.simplydiscus.com/showth...-Water-Changes

I choose to call it the threshold value, so that part of the math is not unique. I did not attempt to calculate "X" which is impossible due to the fact in my example "X" is a fictitious number that covers all water quality variables, you can still chart the degree each water change will make to overall quality.

[John_Nicholson]

Remember folks I have always said that I do not care what any one individual does with their own fish. My problems arise when their unproven speculation causes other new folks to make mistakes. I have always advocated a do it, prove it, then post it kind of a deal.

On this thread the only thing I got out of it is i think I know 2 guys that might share a room together if they come to NADA....LOL.


-john

[brewmaster15]

Remember folks I have always said that I do not care what any one individual does with their own fish. My problems arise when their unproven speculation causes other new folks to make mistakes. I have always advocated a do it, prove it, then post it kind of a deal.

On this thread the only thing I got out of it is i think I know 2 guys that might share a room together if they come to NADA....LOL.


-john

You and Rick? lol
al

[John_Nicholson]

LOL...Nope. I am sure Rick will want to but it is just not my kind of a deal......He will just have to stick with Jim......LOL.

-john

[afriend]

pascal,

I tried to send you a PM but I got back a message that said you were not receiving them. So I'll ask the question here.

I noticed that you did not respond to Post #86. I'd like to take a whack at doing so, but I have no desire to hijack your thread. The questions posed in the post are really interesting and I think that I can add something of value by answering them. So let me know if this meets with your approval. Respond by PM if possible.

Paul

[dprais1]

In the late 70 or 80's Dr Frank De Graaf (curator of the Artis Aquarium in Amsterdam) did an experiment in marine tanks. He started 2 identical tanks with exactly the same set up, water was perfectly clean. In one tank he added nitrate artificially (sodium nitrate for example, it is a salt). He observed that fish were still comfortable up to 1000 ppm and most invertebrates up to 500 ppm. While a nitrate level of 10 ppm in normal conditions is too high. He was the first to talk about other substances in one of his books.

Plantbrain or somebody on Theplanted tank forum also said he used a powdered form of nitrate and maintained it at about 800ppm with no ill effects on the fish involved, tetras i believe.

If I could locate the thread I would add a link. anyhow, his premise is that nitrates are mostly harmless it is doc and such that mess with the fish's health.

[pastry]

On this thread the only thing I got out of it is i think I know 2 guys that might share a room together if they come to NADA....LOL.


-john

My vote for quote of the thread LMAO

[MadMatt]

Can the moderators close this thread!
It's gotten crazy in here with political comments, opinions and off topic beyond!...lol
Just kidding but this has been an interesting thread to say the least!...lol
It's pretty much blown up the forum and the lengthily posts have been more then interesting!
I think I'm going to stick with Rick and just change my water more often then not.

[bluelagoon]

Can the moderators close this thread!
It's gotten crazy in here with political comments, opinions and off topic beyond!...lol
Just kidding but this has been an interesting thread to say the least!...lol
It's pretty much blown up the forum and the lengthily posts have been more then interesting!
I think I'm going to stick with Rick and just change my water more often then not.

Sounds like a good idea.Not only will you be removing the nitrates and other wastes but also replenishing the other nutrients needed for the discus to grow.

[Greg5OH]

regardint he maybe its not nitrates, but DOCs that inhibit growth.
i read somewhere that Jack Wattle said at one time he believed the fish excrete a growth inhibiting hormone. Maybe this is true, maybe its jus tthe DOC's that cause the stunted growth.
My assumtion to this, if it is not nitrates or ammonia that are inhibiting growth, but the fish senses the DOW, which is somehow..different than nitrates (what other compound comes from broken down urine and feces???) and the fish sense this, and slow down growth because it is programmed in their DNA, to not grow big as the environment could support their larger mass? (food, water quality).
I am just talking out of my ***, as I really don't know much about biology, other than plants are great!
What I do know is..I need to set up a permenant water change hardline, so all I have to do is turn a few ball valves to drain and fill. So dang annoying messing around with hoses, getting the carpet wet, having the hose slip out etc..