Wild caught A. Ortegai shyness and hiding

[TacocaT]

Have you any idea what causes the Cyanobacteria?
Do you have other tanks? Are they the same?

I have other tanks but not in this location with this water. The only cyanobacteria that occurs in those is beneath the substrate against the glass, which makes sense due to the anoxic conditions and lighting.

my best guess is that I may be overfeeding, as I've been attempting to build a mulm layer by dispersing leftover blanched vegetables (For the catfish and snails) instead of removal. However, there doesn't seem to be a significant decrease in water quality and the water lettuce isn't taking off, which I usually find happens when there's too much nitrates from leftovers.
I will be feeding them less though from now on at once every other day for frozen food/sinking wafers and some flakes for the tetras daily.

 

[MacZ]

Trust me. I have been trying my best while avoiding using chemicals. I added ramshorn snails last week and I’ve been removing as much as I can every other day to no avail.

Next time I clean the filter I’ll add some dried Cyanobacteria there, as I heard that does something. Why? No idea but it’s worth a shot.

Besides blackouts I have had good results with raising water current in the areas they grow, sometimes just fanning them several times a day with a spoon and they dissapeared after a week. The bacteria hate it. Alternatively some people had success with using starter bacteria in a bottle.

Have you any idea what causes the Cyanobacteria?

That is probably the biggest problem with Cyanos. Nobody ever really knows because there are so many species of these bacteria. Not even full lab water analysises have helped.

 

[MacZ]

my best guess is that I may be overfeeding, as I've been attempting to build a mulm layer by dispersing leftover blanched vegetables (For the catfish and snails) instead of removal.

This is likely the cause by raising phosphates. If you want to build up a mulm layer only use dry and dead plant material like brown leaves and dried twigs. stuff that doesn't contain a lot of nutrients anymore, but never let it build up from food leftovers.

 

[TacocaT]

Besides blackouts I have had good results with raising water current in the areas they grow, sometimes just fanning them several times a day with a spoon and they dissapeared after a week. The bacteria hate it. Alternatively some people had success with using starter bacteria in a bottle.

I highly doubt it's lack of oxygenation or water movement, as I can tell that there is flow throughout the whole tank, and I always keep a permanently running backup airstone inside the tank along with the canister filter. My next water change I'll remove all the gunk and replace with leaves and whatnot.

 

[MacZ]

I highly doubt it's lack of oxygenation or water movement, as I can tell that there is flow throughout the whole tank, and I always keep a permanently running backup airstone inside the tank along with the canister filter.

It's not about oxygenation or general water flow. Cyanobacteria do not do well with stronger water movement. You have to actually stirr them a bit up. It makes the colonies shrink, because it's outside their optimal conditions.

My next water change I'll remove all the gunk and replace with leaves and whatnot.

Good. And of course try to remove as much of the cyanos as possible.

 

[anewbie]

I don't think it is phosphate related; as i tend to do weekly 50% changes and i have some very unpopulated aquariums develop cyano as well as some heavily populated ones. I personally haven't seen a pattern. I'll have one tank that never develop cyano and one next to it that will develop cyano twice in 3 years.

 

[MacZ]

I don't think it is phosphate related

It is one of the many possibilities, especially if the nitrogen compunds are not raised.

 

[anewbie]

I don't think it is phosphate related; as i tend to do weekly 50% changes and i have some very unpopulated aquariums develop cyano as well as some heavily populated ones. I personally haven't seen a pattern. I'll have one tank that never develop cyano and one next to it that will develop cyano twice in 3 years.

So these are some things i've observed with my aquariums over the years:
a) tap water aquaruim almost never get cyanbacteria - maybe one out of 10 in 8 years.
b) co2 injected aquariums can get massive cyano bacteria
c) blackwater aquarium under some unknown condition will get cyanobacteria
--
the things is that it is easy to get cyanobacteria if you inject co2 and blackwater aquariums have a lot of co2. Not saying the co2 triggers the cyano but i think it is one of the contributing factors.

 

[TacocaT]

So these are some things i've observed with my aquariums over the years:
a) tap water aquaruim almost never get cyanbacteria - maybe one out of 10 in 8 years.
b) co2 injected aquariums can get massive cyano bacteria
c) blackwater aquarium under some unknown condition will get cyanobacteria
--
the things is that it is easy to get cyanobacteria if you inject co2 and blackwater aquariums have a lot of co2. Not saying the co2 triggers the cyano but i think it is one of the contributing factors.

Why do you say blackwater has higher co2?

 

[anewbie]

Why do you say blackwater has higher co2?

This is what 'ai' says - i think it is mostly but not completely accurate:
-

Yes, RO water can absorb more CO2 from the air than tap water because it lacks minerals that act as a pH buffer. While RO water is initially neutral, it becomes acidic more quickly when exposed to air, a process that can be accelerated by its lack of buffering minerals. Tap water's dissolved minerals resist this change, so it absorbs less CO2 and its pH stays more stable.
---

Basically i presume the acidic nature of pure water implies a greater amount of co2; non ro water can be made acidic via other means.

 

[Ben Rhau]

This is what 'ai' says - i think it is mostly but not completely accurate:
-

Yes, RO water can absorb more CO2 from the air than tap water because it lacks minerals that act as a pH buffer. While RO water is initially neutral, it becomes acidic more quickly when exposed to air, a process that can be accelerated by its lack of buffering minerals. Tap water's dissolved minerals resist this change, so it absorbs less CO2 and its pH stays more stable.
---

Basically i presume the acidic nature of pure water implies a greater amount of co2; non ro water can be made acidic via other means.

When CO2 dissolves in RO water, it's quickly converted to carbonates and protons. This is a buffering system that reaches equilibrium with a pH of around 5.5. It's the same buffer that exists in your tap water (though tap water often contains more buffers).

The AI is accurate in the sense that RO water needs CO2 to reach a buffered equilibrium state, but that does not mean that the water has "more" CO2. The fraction of actual CO2 in the water is extremely low.

 

[dw1305]

Hi all,

Yes, RO water can absorb more CO2 from the air than tap water

Don't believe AI.

That is incorrect, the amount of CO2 absorbed is dependent on the amount of CO2 in the atmosphere, via Henry's Law. It is entirely independent of the carbonate buffering system.

<"Andy Pierce's"> post on UKAPS.

Cheers Darrel

 

[Ben Rhau]

That is incorrect, the amount of CO2 absorbed is dependent on the amount of CO2 in the atmosphere, via Henry's Law. It is entirely independent of the carbonate buffering system.

<"Andy Pierce's"> post on UKAPS.

Cheers Darrel

I'm not a chemistry expert, but I think I was incorrect for a different reason than you're saying.

Henry's Law holds for nonreactive gases that don't ionize in solution. Given that CO2 is reactive with water, I expect that it does not fully obey Henry's Law.

Where I'm wrong: I assumed that RO water would absorb more CO2, because it starts with less of all of the dissolved carbon species. What I didn't take into account is that as the water gets more acidic, the accumulation of protons would start to shift the dissociation reaction to the left.

If tap water is already in a buffered state, it has capacity to neutralize the protons and the dissolution reaction can continue moving to the right (grossly simplified, as there are additional reactions with different carbon species). Therefore, the buffered solution could absorb and hold more CO2 than RO.

 

[MacZ]

I can only add from my experience: Pure RO doesn't get overly acidic, as it took what felt like ages until my softwater tanks with pure RO reached even the 6 pH mark while adding humic substances in high amounts.

 

[anewbie]

I can only add from my experience: Pure RO doesn't get overly acidic, as it took what felt like ages until my softwater tanks with pure RO reached even the 6 pH mark while adding humic substances in high amounts.

Werid - my discus tank reached 5.8 without much in the way of humic substances. The tank was quite large and the discus didn't need the leaves for cover - however it did have massive plant growth - and a fair amount of drift wood so perhaps that contributed to the drop in ph ?

 

[dw1305]

Hi all,

Henry's Law holds for nonreactive gases that don't ionize in solution. Given that CO2 is reactive with water, I expect that it does not fully obey Henry's Law.

I think it is and it isn't.

I've not had a good record with the chemistry of Dissolved Inorganic Carbon (DIC), but I think that:
Only a really tiny fraction (0.15%) of the dissolved CO2 becomes <"H2CO3">, which then disassociates into a proton (H+) and bicarbonate ion (HCO3-).

The hydration equilibrium constant at 25 °C is [H 2CO3]/[CO2] ≈ 1.7×10−3 in pure water and ≈ 1.2×10−3 in seawater. Hence the majority of carbon dioxide at geophysical or biological air-water interfaces does not convert to carbonic acid, remaining dissolved CO2 gas

Acids are <"proton donors"> and we have added a proton, so pH falls unless there is a a proton acceptor present.

however it did have massive plant growth

Back to Andy Pierce at UKAPS, but I think plant growth should raise pH if the plants are taking-up nitrate (NO3-) -

This one is really worth a read: <"https://niade.com/planted-aquarium-ph-drift-kh-nitrate/">.

cheers Darrel

 

[Ben Rhau]

Only a really tiny fraction (0.15%) of the dissolved CO2 becomes <"H2CO3">, which then disassociates into a proton (H+) and bicarbonate ion (HCO3-).

Yes, but assuming the tap water is buffered, it will consume the protons in the dissociation reaction, pulling that reaction to the right. So the total DIC will be higher in tap water, but the fraction that remains as CO2(aq) will be the same in both.

 

[dw1305]

Hi all,

Yes, but assuming the tap water is buffered, it will consume the protons in the dissociation reaction, pulling that reaction to the right. So the total DIC will be higher in tap water, but the fraction that remains as CO2(aq) will be the same in both.

Yes, I think that is what this plot shows (from the <"UKAPS link">) original at <"https://www.aqion.de/site/159">

The above shows the total amount of DIC (light blue curve) sharply increasing at pH 6 and higher. Note the Y axis is plotted on a log scale. There are both <"relatively easy to digest"> and more <"rigorous mathematical descriptions"> of the concept available.

<"Fireplace Aquarium | Planted freshwater aquarium blog">

cheers Darrel

 

[MacZ]

Can you please put that in words someone without a degree or professional experience in chemistry can understand?

 

[dw1305]

Hi all,

Can you please put that in words someone without a degree or professional experience in chemistry can understand?

I'll try, but the pH ~ Carbonate ~ CO2 equilibrium is an area I struggle with.

You always have the same amount of CO2 dissolved in water, but when you have carbonate buffering some of that buffering is in solution as bicarbonate (HCO3-) or carbonate (CO3--), meaning that you have more Total (or Dissolved) Inorganic Carbon T(D)IC.

The <"Bjerrum plot"> (below) represents the pH ~ DIC relationship, but without indicating the actual total increase in DIC.

cheers Darrel