What Exactly Is "it" That Harms Discus

[RipSlider]

Hi Guys.

I'm looking seriously, although sadly, at having to re-stock my tank, and I think that it may well end up a discus tank.

However, I really want to gety to grips with filtration and water quality issues before I even think about stocking them.

I know that Discus need very good water. This is stated everywhere. And I know that if they don't have it, they get ill. Again stated everywhere. However, what I am really looking for is the answer to the question:

"What EXACTLY are the key chemicals/pathogens that are so damaging to Discus?"

Some people have said Nirtate, but Nitrate can be removed completely with some forms of filtration, so I guess if it WAS this, then it would be being done already. Others have suggested a biological issue, but again this could be dealt with, but isn't being.

Hoes anyone know if there has been any research regarding the exact water quality issues that affect cichlids so badly? If so, please could you point me towards them?

Many thanks indeed.
Steve

 

[The-Wolf]

The most common problem associated with discus is hole in the head (HITH) disease
or to give it its proper name Hexamita caused by a flagellated protozoan bacteria.
This is, 99% of the time, caused by poor water quality and or diet & can therefor be prevented by a good matainance and diet regime.

NitrAte (NO3) is belived to be a growth inhibitor for discus so one should aim for NO3 to be no more than 10ppm, easily done with heavy planting, something else that discus prefer.

There are some conflicting reports that houseing discus and angels together will promote a parasite to traverse both species, this parasite is harmless to angels but often deadly to discus. I'm keeping an open mind on that subject but felt it worth mentioning.

HTH

 

[kev_kb]

In short if you find a decent Discus supplier, match their parameters with regard to hardness and buy fish above 3-4" and keep suitable (gentle) tank mates, you should do fine with Discus. Assuming you feed them properly and keep the tank really clean, look at 2 water changes a week min, then they are no harder to keep than other fish, just a little bit more sensitive that's all.

If you want to raise them from babies then a bare bottom tank is a must IMHO and ideally you'd buy more than you intended to keep as they like to be in groups. It's very easy to stunt baby Discus, so I recommend larger fish, plus they settle in a whole lot better in my experience.

 

[RipSlider]

This is the thing I'm trying to answer.... WHY do they need this different treatment.

I can understand pH sensitivity, that bit I get. However, what aboyut discus means that they need two water changes a week. What is it, in the water itself, that is building up and causing harm.

Equally, what happens if you DON't do two water changes a week? What are the symptoms?

If it is a much greater propensity for HITH, then, as a bacteria, it should be able to be counter-acted with LOTS of UV and an ozone treatment. If it's a chemical issue, then perhaps there is a way to render this chemical safe.

The reason I'm asking is that I have a very large tank, and I'm a way from home a lot. Lots of water changes mean lots of cost and time, and also Mrs Steve isn't prepared to do them. However, if there is a specific issue that I can in some way counter-act then this will make it easier.

What I really don't want to do is get discus and not be able to keep them in the best of health.

Steve

In short if you find a decent Discus supplier, match their parameters with regard to hardness and buy fish above 3-4" and keep suitable (gentle) tank mates, you should do fine with Discus. Assuming you feed them properly and keep the tank really clean, look at 2 water changes a week min, then they are no harder to keep than other fish, just a little bit more sensitive that's all.

If you want to raise them from babies then a bare bottom tank is a must IMHO and ideally you'd buy more than you intended to keep as they like to be in groups. It's very easy to stunt baby Discus, so I recommend larger fish, plus they settle in a whole lot better in my experience.

 

[Tolak]

They need this treatment because they are sensitive, not hardy fish.

Heximita, the internal protozoan mentioned, is a common part of the digestive flora of many fish. As long as they aren't stressed, they get by just fine with it. Stress lowers an animal’s natural immunity & defenses towards bacteria, protozoa’s, or whatever. Discus are sensitive, easily stressed fish. The water they come from has no nitrates, as do most other bodies of water. Hardier fish can tolerate nitrates, discus, being sensitive, can't. This allows the internal protozoan to multiply. Symptoms are not eating, hiding towards the bottom or back of the tank, and whitish feces. Since it's an internal protozoan, all the uv in the world won't help, preventive meds can't kill all of them, you keep them at bay by preventing stress.

Most breeders I know keep pairs in a 29, and do water changes daily or every other day. These are fish that are fed well, so water fouling is an issue, as is the added stress from breeding. I don’t see why an adult pair in a 55 that aren’t constantly breeding couldn’t get by with weekly water changes, or a pair in a 110 every other week. Doing the math, a pair in a 220 would need monthly water changes.

The only problem with this that I can see would be that the soft water discus require would be prone to the pH shifting over time.

 

[plantbrain]

Let's be specific here with respect to NO3 to prevent myths that run rampant in this hobby.

NO3 does not start out as NO3 in planted nor other tanks unless you add KNO3 etc.
I routinely add 20-40ppm of NO3 and have gone to 100ppm with Discus using KNO3.
The fish have had no adverse effects of any sort for a decade.

Now high levels of ammonia, too many fish, too much left over rotting food....that is what the real issue is, not so much the end product of that, NO3.

When you have higher fish loading/feeding, this places more demand on the plants/bacteria/rouitne water changes etc, that in turn lowers O2 by bacterial processing, add some higher temps and faster rates of respiration(and O2 consumption by bacteria) so you have more issues than mere misaligned NO3.

Plants will remove NH4 directly before the bacteria get a hold of it. It's almost never seen(any trace of NH4) in any planted tank. CO2 has no impact on Discus at 30ppm or so either.
This is a huge myth proported by discus zealotry and myth makers.
Some Discus experts still contend this for some reason, just because you are good with Discus does not mean you are good with plants nor have a good understanding of the parameters and their effects.

The issue is low O2, this is very easily noted and addressed by adding more surface moevement and ensuring good O2 and adding more CO2 to make up for the losses.
You may also use pure O2 gas and also see this effect.
Color, vitality, appetite all return.

Not testing to see if the hypothesis holds up or not will lead to many myths and have folks worrying about the wrongly accused parameter/s.

I did it a long time ago but I have looked into this rather than going along with the crowd and actually tested using things like O2, NO3, NH4 etc

Observations are fine and all, but experimental dosing will tell you a lot more about what is really going on.

Discus are fairly hardy, nice fish to keep.
Do frequent large water changes with moderate to soft KH's, feed well, address compatability issues, add enough fish, have a large enough tank etc.

Regards,
Tom Barr

 

[RipSlider]

If it's low O2, then this is really easy to remedy. Also, if I remedied it with ozone, which i already have the kit for, it would kill a lot of pathogens and cuase oxidation in a lot of other nastys. Therfore, it seems a good answer. The question therefore is why hasn't this been done sooner?

Steve

 

[plantbrain]

There are those that do and those that do not.


But in defense, many Discus breeders etc, often have little need nor desire to test such parameters.
This issue is not only true for Discus, but most fish when folks add NO3, CO2, have planted tanks etc.

I've run up to 160ppm of NO3 using shrimp, and they did die after a 3 day exposure.
Fish where fine though.

Sometimes simple quait mythical explainations sound better and are easy to explain that a series of cascades and doing experiments.

You need the motivation to look into the issue also.

O3 has other properties and can cause issues in many cases if not used correctly, but it'll roast the organics very well. For adding O2, using the O2 gas method and a DO meter is more effective in terms of biological impacts from oxygen levels.

I maintain about 8ppm. Darkened Discus appears at about 4ppm.

Generally, many folks try and reduce the current in Discus tanks, they also do the same for planted tanks using CO2 to prevent off gassing, but gas is cheap, and can be turned up to account for some slight loss.

This results in lowered O2 levels, then you add high temps=> faster bacterial respiration and less O2 at stauration levels than cooler water, you get problems. Discus folks spend too much time playing with Conductivity, that does not tell you specifically what ions are present, only ones that conduct.

Likewise, water changes and KNO3 is cheap, and most Discus folks do large weekly water change anyway.
Much like many plant tank folks. Other fields can help other areas in the hobby, often there's not a need for such info since many have bare bottom tanks and like those huge water changes. That works for good fish and health. But it does not answer whether or not something is true in tetrms of a myth that the fish like or dislike something.

Observation alone will only get you so far and speculate so much.
From there you need to do experimentation.


Regards,
Tom Barr

 

[kev_kb]

You need to consider that a healthy discus should have a life span of around 10 years, so your experiments may not kill the fish but could seriously affect this. Regardless of the species being kept regular water changes are invaluable, and this applies even more so to Discus. I think you need to decide how much time you could devote to the tank and then decide if Discus are for you. As you say, if there is an easy way to keep them without regular water changes then surely everyone would be doing it.

 

[RipSlider]

Kev_bh.

I totally agree that if I will only keep discus if I know I can keep them correctly and healthily. However, equally, while I'm happy enough doing 1 water change every 7-10 days, multiple water changes a week from a 600l tank will rapidly become an issue in terms of cost for the RO and also time. I am away from home for at least 3-4 days most weeks, so while the fish will be fed and monitered ( Mrs Steve is happy enough with this ) she won't do, and I don't want her doing, water changes with RO/buffer etc.

Your comment about "if there was a better way, surely everyone would do it?" was what set me thinking in the first place. When I read books on discus, or the discus forums, there seems to be a religous belief that Discus need very frequent water changes.

This makes me ask two questions:

1) What happens if they DON'T have frequent water changes. I.e what are the physical symptooms that are cuased

2) What is "it" that is being removed during these water changes that makes discus so much more healthy?

If you look at it in another way, Marine fish are, in general, far more sensitive to poor water quality than Dsicus, but they do not have multiple water changes/week. The most stunning that that I have seen has a water change every three weeks. I know that in marines there are other "helpers", like skimmers etc, but there didn't used to be, until someone sat down and invented and refined them.

All I'm wondering is, if the source of the problems can be identified, can I work out a way of getting rid of it. Before I do this, I have to know what the "it" is.

Steve