Smelly tank water

[rthomas]

This is a 160g tank with pressurized CO2 system. The tank has been setup for about 3 months. The front is HC covered for about 70% . Their growth is not that excellent though. I too have some 6 to 8 clumps of Blyxia in this Iwagumi styled tank.

The tank also have some algae. Looks like staghorn. The surface looks like it have some sort of scum. If I were to make my Koralia output pointing slightly to the surface, that will form many bubbles that last for ages.

For the past 2 weeks I noticed that the tank started to smell like a fish market. The ADA soil does not stink. Only the water is giving that smell. You know that smell that rushes into your nose when you go into a fish market.

It is disturbing the rest of the family members and very embarrassing when we have visitors. To make matter worse, the tank sits very close to the dining hall.

I would give excuses to others not to dine with us for the moment until I am able to solve this problem. Guys please help.

--
Roger

 

[Gerryd]

Hi Roger,

A couple of questions:

1. Do you have any BGA? This stuff can be really rank.

2. Are there any dead or missing fish in the tank? Obvious I know but had to ask.

3. Does the tap or water you use for WC have a scent at all?

4. Is it more like rotten eggs? This is sodium chloride and is deadly to fish. Any large smelly bubbles come up when disturbing the substrate?

5. The HC growth is most likely c02 and/or current. All plants should grow well by 3 months into it.

6. Are you sure it is cycled? I have heard Tom mention high NH4 levels for a LOOOONG time use ADA substrates. Not sure if this has anything to do with smell, but figured I would ask........

7. Surface scum points to either heavy feeding or insufficient nutrients.

8. Any differences in routine or maintenance in the last couple of weeks?

9. Filters clean and in good shape?

I wish I could help more, but I have never heard of this..........

Hope this helps somehow......

Best of luck.

 

[SuperColey1]

Hi Roger,
4. Is it more like rotten eggs? This is sodium chloride and is deadly to fish. Any large smelly bubbles come up when disturbing the substrate?

Its not Sodium Chloride. That would kill all the plants and life very quickly.

The 'anaerobic' areas create Hydrogen Sulfide which is also deadly to life which quickly fuels the 'sand has a problem with anaerobic areas' myth, however once Hydrogen Sulphide comes into contact with O (The instant it gets to the oxygenated water) then it turns to Sulfur Oxide which is harmless to fish.

It is the Sulphur Oxide that smells like rotten eggs.

Anaerobic areas should be good in a planted tank from my memory!!!

AC

 

[rthomas]

Thanks Gerry dan AC.

1. Do you have any BGA? This stuff can be really rank.

2. Are there any dead or missing fish in the tank? Obvious I know but had to ask.

3. Does the tap or water you use for WC have a scent at all?

4. Is it more like rotten eggs? This is sodium chloride and is deadly to fish. Any large smelly bubbles come up when disturbing the substrate?

No.

5. The HC growth is most likely c02 and/or current. All plants should grow well by 3 months into it.

Thing looks good.

6. Are you sure it is cycled? I have heard Tom mention high NH4 levels for a LOOOONG time use ADA substrates. Not sure if this has anything to do with smell, but figured I would ask........

I dry-start the tank 5 weeks before flooding.

7. Surface scum points to either heavy feeding or insufficient nutrients.

There are only 6 Ottos and 5 SAEs. I don't even feed them. But I was quite lean on fertz with EI: 1.25 tsp KNO3, 0.5 tsp KH2PO4 and 0.24 tsp trace. 50% WC weekly.

8. Any differences in routine or maintenance in the last couple of weeks?

No.

9. Filters clean and in good shape?

Not very clean. I just cleaned them today.

 

[Gerryd]

AC,

Thanks for the correction. It was late when I posted..........at least that is my excuse. Not sure why I was thinking Sodium Chloride

 

[SuperColey1]

I read it and thought. Thats what they used to use in weedkillers isn't it? lol

AC

 

[jmacego]

Not sure about sodium chloride in weed killers, but I know it's great on slugs, it does kill plants, too. But, I really prefer to use it on food. (table salt)

The joys of forums, especially to those of us late night posters (who tend toward more mistakes), is we get to have our mistakes out for everyone to enjoy!

 

[Brian_B]

Chemicals

Hello everyone!

Rotting fish (and fish markets) smell from mainly ammonia and organo-sulfo-phospho compounds, and aromatics with dangling NH groups. Washing a dead fish in lemon juice is helpful for deodorizing because it stabilizes the NH3 into an NH4 salt and keeps some of the other alkaline compounds in solution too.

The dangerous bubbles that come from fish tank bottoms are hydrogen sulfide, which is acidic and lethal to almost everything, including humans. It smells like rotting eggs. Hydrogen Sulfide does NOT spontaneously (i.e., without catalysts, enzymes, or heat) turn into Sulfur Dioxide, or it would not be toxic, because entering human blood (which is very highly oxygenated) it should be rendered inert. But, it is toxic, therefore it doesn't spontaneously oxidize. Also, H2S is not very soluble anyway because it is a very weak acid, meaning trace amounts are lethal. You can turn it into SO2 by burning it. Eventually it can convert to SO2 at room temperature (due to entroptic randomness) but by the time this (probably years) happened the fish would be dead and so would you. Basically, it is not a good thing, and it should be avoided. Ammonia, however, will NEVER bubble out of a live tank, because it is incredibly water soluble. It still evaporates, though.

Sulfur Dioxide is not really good either, but it's very water soluble (forming sulfurous acid) and not very dangerous (except as an acid). It also cannot bubble out of a tank, and you will never smell it from a tank that has a single live thing in it.

Sodium Chloride is the stuff in a salt shaker. That is safe; in fact there is an expression "less toxic than table salt" and variants. Dumping a handful of salt in your tank won't usually hurt anything unless it is iodized - iodine is toxic, not sodium chloride. NaCl will bubble out saltwater tanks, if you set your aquarium heater to 1738 Kelvin, so don't do that.

Inorganic weedkillers typically use sodium hypochlorite (bleach) or sometimes chlorite. Weedkiller is not good for aquariums, but fortunately it doesn't form in the substrate or bubble.


I would suggest a large (50%) water change, scrubbing the tank sides, lightly vacuuming (not stirring) the gravel, and thoroughly cleaning the filter media (in the tank water that you are going to dump). Then skip fish food for a day, skip fertilizer for a week or two at least, increase aeration to the maximum for a while, and try not to let it happen again by preemptively doing water changes and filter cleanings, and generally using less fertilizer.

However! I know more about chemistry than I do about aquariums, and I have not taken any chemistry for a decade, so I'm only speaking from theory and you may do better by ignoring my aquarium suggestion. There are a lot of other possibilities like mold infestations.

 

[rthomas]

I would suggest a large (50%) water change, scrubbing the tank sides, lightly vacuuming (not stirring) the gravel, and thoroughly cleaning the filter media (in the tank water that you are going to dump). Then skip fish food for a day, skip fertilizer for a week or two at least, increase aeration to the maximum for a while, and try not to let it happen again by preemptively doing water changes and filter cleanings, and generally using less fertilizer.

I thought skipping fertilizer in an attempt to fight algae is not a good idea? Instead we still dose lightly (probably half the normal dosage) ?

I could be very wrong. Please advise.

 

[Gerryd]

Well, if the thought is that the ferts are the cause of the odor, then no you shouldn't use them.

However if this is not the desire, then IMO/IME ferts can and should be added to the tank during blackouts or in your situation. I did my BO this way and it seemed fine. If the ferts are not thought to be a cause of the issue, then I would dose normally. I would tend to think the ferts themselves are not the issue, but certainly have been wrong before........

You can easily dial it back N % if you desire, but if doing a 50% WC there is no need to limit your dosing...

I like the advice, maybe do this for 2-5 days. Daily 50% wc can help in many ways to at least get the tank under control quickly so you can then see where the problems are. I dose every WC when doing those extended times when doing daily or more WC to reset and help with a specific issue. Like when doing daily 50 after new fish are added for 3-5 days........

How is the problem? Better or worse?

 

[SuperColey1]

If the problem is to do with the substrate then not dosing will make the plants suffer and they will then stop pulling from the substrate which I would've thought would make the problem worse.

I can't see it being a problem to do with ferts at all.

AC

 

[rthomas]

Thanks Gerry and AC.

As mentioned I have started to notice Staghorn algae. The smell is still there. I did 50% WC every other day and dose half EI for my tank size.

I have removed most of the algae and intend to do daily 50% WC for maybe a week. During that time I might also continue do dose half the normal EI amount.

 

[Brian_B]

I thought skipping fertilizer in an attempt to fight algae is not a good idea? Instead we still dose lightly (probably half the normal dosage) ?

I could be very wrong. Please advise.

My assumption is that any water with a foul-smelling film on the surface has too many nutrients, way too much organic content, and too little oxygen. Personally... I don't know what blue-green algae smell like or the best methods of fighting it through gradual feedback mechanisms, so if that's the problem, perhaps my advice is wrong? However, it sounds to me like the water has simply gone foetid, which is a neat-looking word that means fetid. This is a generalized symptom describing a huge variety of specific 'diseases', but the root of all of them is a combination of:

1) Too many nutrients (organic - by which I mean meaning they have carbon-carbon bonds and other stuff too)
2) Too many nutrients (inorganic)
3) Not enough oxygen
4) Stagnation (not enough motion and turbulence)

(Note that not all of these 4 things are necessary.)

Plants do not benefit from dead organic matter in the water; unwanted unicellular organisms - particularly yeasts, fungi, and anaerobic bacteria - do. Plants cannot clear this stuff out so you have to take it out with water changes, and fertilizers make planktons bloom and die, replenishing the stuff. In short, the water is too rich, and generalities like 'don't halt fertilizer to reduce algae growth' are not applicable to all situations - particularly not when the problem is purification due to excessive nutrient concentration.

Again, the problem COULD be cyanobacteria of which I know very little except that they smell bad, or a dozen other diseases of which I know nothing. But I would strongly recommend what I recommended since I think that purification is the most likely problem.


P.S.

50% WC every day sounds like too much. If after 3 50% changes the smell is not gone, then either
1) It is residual and will fade away on its own
or
2) It is caused by some other infection and I was wrong about excessive nutrients being the cause.

You may want to look into:
Activated Carbon, which will absorb smelly chemicals. If the odor is lingering after the problem is solved, fresh carbon in your filter will get rid of it. And in any case carbon will neutralize the odor for a while (but take some of the useful nutrients out of the water too).
Hydrogen Peroxide. Sometimes used to treat fish parasites and algae problems. It is like a neutron bomb and sort of a last resort because it destroys biological filters. But at the right dose it is very useful, killing unicellulars without hurting plants or fish very much (like radiation therapy for cancer patients). It also destroys smelly chemicals, and disappears without a trace after minutes (exact time depends on various factors). If you use peroxide be sure to research the dosage and methodology first and have some water from a healthy aquarium on hand to dump in a few hours later, to re-introduce denitrifying bacteria and etc.

 

[ceg4048]

My assumption is that any water with a foul-smelling film on the surface has too many nutrients, way too much organic content, and too little oxygen. Personally... I don't know what blue-green algae smell like or the best methods of fighting it through gradual feedback mechanisms, so if that's the problem, perhaps my advice is wrong? However, it sounds to me like the water has simply gone foetid, which is a neat-looking word that means fetid. This is a generalized symptom describing a huge variety of specific 'diseases', but the root of all of them is a combination of:

1) Too many nutrients (organic - by which I mean meaning they have carbon-carbon bonds and other stuff too)
2) Too many nutrients (inorganic)
3) Not enough oxygen
4) Stagnation (not enough motion and turbulence)

(Note that not all of these 4 things are necessary.)

Plants do not benefit from dead organic matter in the water; unwanted unicellular organisms - particularly yeasts, fungi, and anaerobic bacteria - do. Plants cannot clear this stuff out so you have to take it out with water changes, and fertilizers make planktons bloom and die, replenishing the stuff. In short, the water is too rich, and generalities like 'don't halt fertilizer to reduce algae growth' are not applicable to all situations - particularly not when the problem is purification due to excessive nutrient concentration.

Again, the problem COULD be cyanobacteria of which I know very little except that they smell bad, or a dozen other diseases of which I know nothing. But I would strongly recommend what I recommended since I think that purification is the most likely problem.


P.S.

50% WC every day sounds like too much. If after 3 50% changes the smell is not gone, then either
1) It is residual and will fade away on its own
or
2) It is caused by some other infection and I was wrong about excessive nutrients being the cause.

Hi,
There are only a few reasons why there should be organic waste in the water column and these include the fauna dying and fouling the water or plants suffering and their tissues dying and fouling the water. A low oxygen content would be due to poor plant performance. If we eliminate dead fauna as a possible cause then the strongest source of organic matter ejection into the water column will be excretion due to poor nutrition.

If the filters were cleaned and subsequent large water changes failed to eliminate the odor then this points to continued production of organic waste, which likely means continued nutritional deficit.

In fact, plant are very capable of removing the organic matter as it decays and produces ammonia, however in a highly lit tank this is not really ideal as the combination of high light and ammonia will induce algae.

If the problem was caused by poor nutrition then the only solution is to improve the nutrition by the proper addition of inorganic fertilizer and/or CO2. If the proper levels are being added and the situation remains unchanged then flow/distribution is suspect.

The OP indicates that BGA is not present therefore cyanobacteria cannot be a cause of the odor (BGA=cyanobacteria). In such a large tank however flow and CO2 distribution must always be under suspicion.

The dosing regimen is also suspect:

...I was quite lean on fertz with EI: 1.25 tsp KNO3, 0.5 tsp KH2PO4 and 0.24 tsp trace. 50% WC weekly...

It's unclear what the lighting level is, or what the PO4/NO3/trace level of the source water is but this sounds quite low. In order to eliminate poor nutrition as a possible cause it's advisable to dose at least the recommended EI levels. Using fractional dosing on large tanks under high light (if indeed the light is high) is never a good idea. There is absolutely no way that a rich inorganic content can cause this issue. There is simply too much empirical evidence to the contrary. On the other hand, poor dosing techniques, poor CO2 and poor flow/distribution have been found to be the direct or indirect causes of a myriad of problems, especially in a large tank.

I agree that activated carbon will help but lean dosing will generally cause more problems than it solves. The appearance of surface scum is a classic indication of sub-par nutrient/CO2/flow so I would rectify these areas first. A 160G tank ideally could use a total flow rating on the order of 1600 GPH (combination of filter rating + powerhead rating)

Cheers,

 

[rthomas]

Brian and Ceg4048, it is very inspiring to read both of your comments. I thank you all.