Scientific Question on Water organics / inorganics

[dominicreeks]

Hi all, I hope this is the correct place to post... Please correct me if not I am new.

If a fish keeper monitors nitrates and keeps them low - either with plants or mAb coated media - it appears from all my reading and other keeper's experience that water changes are still important. I do not doubt this - however, I have not seen an explanation as to what builds up in the water to mean water changes are required to maintain water quality. Can anyone point me to any journals that investigate water quality? perhaps by Mass Spec or Gas Chromatography? I would really like to find out.

I should add context - my aim is not to efficiently increase the size of or breed discuss. Simply to keep my Discus healthy. I am also a microbial physiologist, I understand that the discus are sensitive to bio-burdon, presumably Fish keepers perform water changes to keep this lower too - but has anyone experience of measuring bio-burden? I assume most don't have access (take the time to perform) to spread plate analysis - therefore if people do measure bio-burden how? perhaps by dissolved oxygen (DO)? and if DO is there a hobbyist DO probe? and one last question: is UV exposure effective at reducing bio-burden - bringing me to my original question what is in the water other than nitrates that necessitates frequent WCs?

Please note I am not asking as a means to "get out of changes". I am asking because I have a curiosity for the biological cause and effect.

Thank you all - Dominic

UK Based, Planted tank (at the moment soon to be bare bottomed potted plants), 200L municipal water, 1x Pigeon Blood, 1x blue (hopefully 4 more when tank optimal), 28.8C, pH 7.6-8, Nitrates - about 5ppm, currently weekly water change also not sure whether use carbon (unsure of heavy metals in municipal water - question for another day )

[For100]

Hi Dominic,

There is a lot of threads in this forum that dig into your questions about water changes/quality. Most info is based in personal observations more than empirical data. Having said that, I recently found this company in Singapore that specializes in planted tanks BUT it provides a lot of information around water chemistry and biology of enclosed system (aka aquariums), they have some good data points to support their approach.

Bottom line is that even if you only keep plants, they recommend at least a 50% water change weekly to maintain stability of water chemistry.

Here is the link in case your interested…. There is a whole section around water parameters and such.
Hope it helps.

https://www.2hraquarist.com/blogs/ph-kh-gh-tds

[brewmaster15]

Hi all, I hope this is the correct place to post... Please correct me if not I am new.

If a fish keeper monitors nitrates and keeps them low - either with plants or mAb coated media - it appears from all my reading and other keeper's experience that water changes are still important. I do not doubt this - however, I have not seen an explanation as to what builds up in the water to mean water changes are required to maintain water quality. Can anyone point me to any journals that investigate water quality? perhaps by Mass Spec or Gas Chromatography? I would really like to find out.

I should add context - my aim is not to efficiently increase the size of or breed discuss. Simply to keep my Discus healthy. I am also a microbial physiologist, I understand that the discus are sensitive to bio-burdon, presumably Fish keepers perform water changes to keep this lower too - but has anyone experience of measuring bio-burden? I assume most don't have access (take the time to perform) to spread plate analysis - therefore if people do measure bio-burden how? perhaps by dissolved oxygen (DO)? and if DO is there a hobbyist DO probe? and one last question: is UV exposure effective at reducing bio-burden - bringing me to my original question what is in the water other than nitrates that necessitates frequent WCs?

Please note I am not asking as a means to "get out of changes". I am asking because I have a curiosity for the biological cause and effect.

Thank you all - Dominic

UK Based, Planted tank (at the moment soon to be bare bottomed potted plants), 200L municipal water, 1x Pigeon Blood, 1x blue (hopefully 4 more when tank optimal), 28.8C, pH 7.6-8, Nitrates - about 5ppm, currently weekly water change also not sure whether use carbon (unsure of heavy metals in municipal water - question for another day )

Hi Dominic, Welcome to SimplyDiscus!

Your first post as a member is certainly a challenging one. Its a pretty heavily discussed and debated topic among discus Keepers. Nitrates are a factor, Discus do not do well with them. But there are other factors that lead to improved health, growth and longevity of discus in captivity and frequent water changes is a major one. Its not something thats been quantitatively determined, and is not in journals simply because in aquaculture Discus are not a commercial fish of economic significance. There are very few scientific articles on Discus relative to economically important fish, like zebra fish for research and Salmon for food. Much of what we know comes down to experience. Once you have raised fry from eggs to adult you understand what works and what doesn't . We take that and apply it to what we know of where Discus evolved. These waters where wild discus come from are soft, acidic, low bacterial loads, high in tannins...next to impossible to duplicate in captivity.Add to that we are raising them with a goal that does not go along with how they evolved...meaning we are trying get them to grow big and uniform, round and do so as fast as possible. To do that we feed lots of high protein foods that create lots of wastes. These wastes in turn lead to high bacterial loads and high dissolved organics (docs). In alot of ways how discus are raised is more like intensive livestock rearing. All this leads to poor water quality that goes far beyond simple Nitrate control.

As a side note you may find this article on DOCs interesting..

https://www.nature.com/articles/srep20377



I wish I had science to show you here, I look all the time for articles on these subjects but I can only tell you that if I take a batch of fry , split them into groups, and feed the same, varying water changes and controlling for Nitrates, The two groups of fry will develop very differently. LIkewise I can take two groups and raise one bare bottom in a tank and do many water changes and raise the other in a planted tank with limited water changes , feed same and all other parameters similar and there will be higher mortality in the planted tank, increased disease issues, increased % stunted discus and over all smaller discus than the bare tank. Its not scientific but it has been repeatedly demonstrated time and again.

The real question is how much water change is optimal? Thats up for debate as well, so most do more rather than less if they want the biggest healthiest Discus. For you

I should add context - my aim is not to efficiently increase the size of or breed discuss. Simply to keep my Discus healthy.

That water change amount and frequency will be far less than others here.



Probably not what you wanted to hear? I do hope it helps in someway.

How long have you had Discus?

al

[dominicreeks]

Hi Dominic,

There is a lot of threads in this forum that dig into your questions about water changes/quality. Most info is based in personal observations more than empirical data. Having said that, I recently found this company in Singapore that specializes in planted tanks BUT it provides a lot of information around water chemistry and biology of enclosed system (aka aquariums), they have some good data points to support their approach.

Bottom line is that even if you only keep plants, they recommend at least a 50% water change weekly to maintain stability of water chemistry.

Here is the link in case your interested…. There is a whole section around water parameters and such.
Hope it helps.

https://www.2hraquarist.com/blogs/ph-kh-gh-tds

Thank you very much I will look into this link - much appreciated. Dominic

[dominicreeks]

Hi Al, Thank you so much for your quick and comprehensive reply. Looks like there may be a PhD in this for someone somewhere.

I have kept community fish in a smaller tank for years but never Discus. About 6 months ago I was at a crossroads of giving up or going bigger with my tank.... I chose going bigger. a couple of months later I was at the local fish shop who have been great to me in the past and saw these beautiful 2-3" Discus and took a gamble on purchasing 6 of the most expensive fish I have ever bought and keeping exclusively discus. I learned the hard way I guess... I lost a number of them there always seemed to be one hiding and off food and when that one died the next one took over. Fast forward now - I have nursed the last sick one (pigeon blood) back to health (bacterial infection) and maintained the other (blue) to a point where both are doing really well and come to me for food etc. I am now at that point after reading a lot.... Looking at your fantastic lecture on You tube (how I found this site) to deciding - how to proceed. I have never been very good at giving up... (how I got my PhD) so I think I will go bare bottom - potted plants and when all stable introduce more Discus. I did consider going back to smaller cheaper fish -(actually completely giving it up) but I am fascinated by these animals - I have never known fish to be so interactive. I am also fascinated by the biology.

Dominic

[brewmaster15]

Dominic,
Glad you found us and stuck with it ... its frustrating in the beginning but I am sure you will have less issues as time goes on and you learn more. This forum is the best place to do that so please read much and post often. We have a very diverse group here some have been in the hobby ages others only a short time but in that time they have really learned so much. Hope to see your discus journey here..maybe consider starting a thread in our tank Journal section.Its a great way to share what you are doing and learn.

Al

[Willie]

One of the most interesting reports come from George Farmer, who ranks among the best aquascapers today. He had set up a beautifully scaped tank for discus. Then he put up the following



based on how his discus reacted to a planted tank. Most interesting.

[brewmaster15]

One of the most interesting reports come from George Farmer, who ranks among the best aquascapers today. He had set up a beautifully scaped tank for discus. Then he put up the following



based on how his discus reacted to a planted tank. Most interesting.

Wow! Thats not the kind of videos we normally see about discus in planted tanks.

[For100]

One of the most interesting reports come from George Farmer, who ranks among the best aquascapers today. He had set up a beautifully scaped tank for discus. Then he put up the following



based on how his discus reacted to a planted tank. Most interesting.

Hi Willie,

I saw the same video…. It was impressive the before and after videos. Same fish such a different coloration.

[Vanman]

Is it just me or does the Turk with the stress bars look a little thin?

[brewmaster15]

Is it just me or does the Turk with the stress bars look a little thin?

George actually mentions that in the video Gary.

[CliffsDiscus]

Is it just me or does the Turk with the stress bars look a little thin?

I see a couple with skinny foreheads and the stress out Turk.

[brewmaster15]

George actually mentions that in the video Gary.

A l

[Vanman]

I should pay attention to the audio and not just the video.

[brewmaster15]

I should pay attention to the audio and not just the video.

Lmoa..yep