Purpose of water changes

[bluelagoon]

To make a quick summary of it, having good water quality is not only down to the amounts of nitrogenous compounds in the water column. Water quality is also affected by the toxins released by biomass that accumulates due to uneaten fish food, fish poop etc.

Rather than just applying the generic name of "toxins", is there any literature documenting what these toxins are?

I find the easiest way for me to understand something is to try and pick holes in the theory behind it. I struggle to do any task if the rationale is "because someone said so"

When you keep adding elements from the periodic table (in food, conditioners, ect. and there are lots of them) and not talking them back out, they just accumulate and make the water poison(toxic). Simple.

[Second Hand Pat]

Hi Kean, I am not sure you will find a theory on this however please feel free to look about the forum and online. Most people here on the forum recommend large water changes simply because the fish teach us this is what they require to thrive in the little glass box we keep them in. So practice and experience thru the fish are the best teachers. So we are not the ones who say "because we said so" but instead it is "because the fish said so".

You also might consider reading thru the threads on the last growout contest we had. Lots of good lessons in those threads. Look under the subforum "Discus Grow Out Challenger Contest 2018"

Pat

[coralbandit]

My belief is there are for more things in the water then we could test for even if we knew about them and believed in them ..
Growth Inhibiting Hormones/Growth Inhibiting Factors [GIH/GIF] is IMO another reason to change water as often as possible while growing fish [not just discus ].
https://sci-hub.tw/https://onlinelib...1977.tb04130.x
I am a big water changer ..
One of my buddies says it best IMO .He says ; " Change as much water as possible as often as possible "..
That sounds a lot better then when he says;" you do flush the toilet don't you " ?

[captainandy]

Plus the sludge (slime) hinders the bacteria from getting O2. The bacteria is similar tooth plague attached to surfaces. Filters need regular cleaning, they sludge up too. In time clean water is flowing through this dirty sludge and not cleaning the water properly.

Most denitrification bacteria are anaerobic and don't require O2. Nowhere is there more sludge than in our own treatment facilities.

I keep only large adults and I reduce nitrates by growing algae by a device I used in saltwater reefing. That being said I still do 75% twice a week and I can tell that my guys (and girls) love it.

[LizStreithorst]

Barb did it wrong why back this forum was even a twinkle in someone's eye. She knows how to do it correctly now. She only buys small fish and grows them out herself. They get huge like they're supposed to. Next time I give her a call I'll ask her if she will post to this thread.

[bluelagoon]

Most denitrification bacteria are anaerobic and don't require O2. Nowhere is there more sludge than in our own treatment facilities.

I keep only large adults and I reduce nitrates by growing algae by a device I used in saltwater reefing. That being said I still do 75% twice a week and I can tell that my guys (and girls) love it.

Not sure what algae has to do with sludge. You need both anaerobic and aerobic bacteria for the nitrogen cycle.

[captainandy]

Be happy to explain to you. An algae scrubber is a device that you place in the tank or sump that grows algae in a secluded box. The algae, takes up nitrates and phosphates and the device is cleaned out once every couple of weeks. Believe it or not, low nitrates and phosphates are much more critical factors in growing hard corals than in discus husbandry so often used with saltwater tanks

The reference to sludge was to illustrate the fact that water companies cleanse water thru giant anaerobic/sludge filters and containers to remove most unwanted chemicals and pollutants.

[bluelagoon]

Be happy to explain to you. An algae scrubber is a device that you place in the tank or sump that grows algae in a secluded box. The algae, takes up nitrates and phosphates and the device is cleaned out once every couple of weeks. Believe it or not, low nitrates and phosphates are much more critical factors in growing hard corals than in discus husbandry so often used with saltwater tanks

The reference to sludge was to illustrate the fact that water companies cleanse water thru giant anaerobic/sludge filters and containers to remove most unwanted chemicals and pollutants.

I know all that, you didn't need to explain.

[captainandy]

I am so sorry that I offended you. My comments are directed to the readership.
I do not think that algae scrubbers are widely used.

Also, there was concern about sludge and sludge is where anaerobic bacteria live

[14Discus]

Captainandy,

You are prob correct that algae scrubbers may not be widely used. I will add, though, that this guy uses them in all my tanks and wouldn’t go wo after seeing how well they work to eat up NO3/nutrients. Every time I remove algae, I’m removing growth mass that used my tank water’s garbage nutrients to do so. When using algae scrubbers along with a refugium, resin bags, and nitrate reactors, the NO3 levels stay rather low between WCs. Just my thoughts.

[bluelagoon]

There's a difference in algae scrubbers with light and sludge in the filters or substrate. It impedes O2 for aerobic bacteria. If these aerobic bacterium go without O2, too long and then cycle is interrupted, stalled or not preforming as well as there should. But still they are places in the tank and filters for anaerobic bacteria can grow. Plus algae scrubbers are not in the main tank, they are more like a refugium. I had one on my SW tank when I had one years ago.I don't get offended at any of the comments on here.

[peewee1]

We change the water often for the same reason we change the babies diapers. Bio-load. After a while they begin to stink if not changed. With regard to Discus, they are by nature river fish. Designed to thrive in a river. Be it muddy and silt ridden or somewhat clear the river constantly changes the fishes water. They got used to it for however many years they have inhabited the Amazon.

[fuz940510]

Hi all

Apologies for the delay in replying to this thread.

I think my intent behind this thread has been misinterpreted - I am not aiming to find a way around the water changes. There is plenty of evidence (anecdotal or otherwise) that points out that the best practice of surface scraping followed by big water changes, alongside lots of good food, is the easiest way to grow discus big and healthy. My aim/point of curiousity was to find out exactly what effects the practice was having on water chemistry and the aquarium as a system. By listing examples of alternative practices, i was attempting to highlight my lack of knowledge/understanding of the root problem.

The knowledge shared by Mervin (bluelagoon) about toxins, and Brian (jeep) about bioload/biomass has pretty much satisfied my need for knowledge. The information provided is not easily found, so i'm glad i dredged it up

Cheers,
Kean

[fuz940510]

And, it seems someone here had similar thoughts, and did an experiment: http://forum.simplydiscus.com/showth...algae-scrubber

They just went a bit crazy with the lack of water changes. Even on my current baby tank of green neon tetras and cories i still do a 50% water change every week.

The experiment provided good proof that it's not only about the nitrates though.

[captainandy]

What kind of algae scrubber did you use?