Apistogramma Agassizii

[dw1305]

Hi all,

So what you are saying is that I should add oxygen instead of ammonia?

Yes, that is really the key. I wrote <"Aeration and dissolved oxygen in the aquarium">, about 10 years ago specifically for keepers of large rheophilic plecs, but it has wider relevance, and a lot of the content looks at biological filtration.

Because you have a tank with plants you have a lot more lee way than some-one who keeps a non-planted tank.

cheers Darrel

 

[TuvaM]

Alright. That article made a lot of sense, thanks! I have an O2 diffuser on my filter, should I turn that on then? Or is it enough with the plants? And how do I know if there is enough O2? When NH3/4 and NO2 are being converted to NO3?

 

[dw1305]

Hi all,

Alright. That article made a lot of sense, thanks! I have an O2 diffuser on my filter, should I turn that on then?

Yes, turn the venturi on. During the photoperiod it doesn't really make any difference (because the plants are producing O2 via photosynthesis, and this vastly exceeds their oxygen consumption), but at night the plants are part of the bioload and are oxygen users.

Or is it enough with the plants? And how do I know if there is enough O2? When NH3/4 and NO2 are being converted to NO3?

You can't easily measure dissolved oxygen, but if you have both plants and a large gas exchange surface you will have enough oxygen. If your plants "pearl" towards the end of the photoperiod, that is an indication that you have 100% oxygen saturation.

You can tell plants are net oxygen producers because for every molecule of CO2 that enters the photosynthetic pathway one molecule of O2 is evolved.

At "light compensation point" the amounts of CO2 incorporated and oxygen evolved are in balance and there is no plant growth, but as soon as there is more light (light = "Photosynthetically Active Radiation" (PAR)) then some CO2 is incorporated into carbohydrates.

Because plants grow we know that CO2 consumption exceeds CO2 production (from respiration) and that a rapidly growing plant is both producing a lot of oxygen, and using a lot of CO2.

Aquatic plant growth is often limited by CO2 availability. Aquascapers add CO2, but you can take a different approach where you use floating, or emergent plants. The atmosphere has ~400ppm CO2, compared to ~1ppm in water.

This access to aerial CO2 (and oxygen) is the aerial advantage that Diana Walstad talks about in <"The Ecology of the Planted Aquarium">.

cheers Darrel

 

[TuvaM]

Thank you Darrel! You have been very helpful

 

[TuvaM]

So I added the redmoore root I got yesterday, and the pH has gone down from 7,5 to 6,5. Is this sufficient for the nitrification or should I do something about it? Just to mention, NO2 has gone from 5,0 mg/L to 2,0 mg/L the last two days, and NO3 from 100 to 75 mg/L. Does that add up? I thought NO3 would rise when NO2 sunk.

 

[Mike Wise]

There are nitrifying bacteria that live in waters with much lower pH values. Most of my breeding tank are at ~pH 5.5 (blackwater species) and they have no problems. Maybe your plants are taking up more of the nitrates?

 

[dw1305]

Hi all,

So I added the redmoore root I got yesterday, and the pH has gone down from 7,5 to 6,5. Is this sufficient for the nitrification or should I do something about it?

There are nitrifying bacteria that live in waters with much lower pH values. Most of my breeding tank are at ~pH 5.5 (blackwater species) and they have no problems.

Mike is right, we now know that there are a whole suite of micro-organisms that are involved in nitrification, and that they are much more adaptable and flexible than was initially thought.

Just to mention, NO2 has gone from 5,0 mg/L to 2,0 mg/L the last two days, and NO3 from 100 to 75 mg/L. Does that add up? I thought NO3 would rise when NO2 sunk.

We are just going around in circles here, you have plants, they are growing, planted tanks have a huge amount more bio-filtration capacity than non-planted ones, nitrification isn't reliant on filter bacteria or high pH, tests for NO3- are problematic.

I don't know what else we can say.

cheers Darrel

 

[TuvaM]

Okay, thanks guys! I will continue with what I am doing then. What are your thoughts about pH btw? My tap water has a pH of 8.0, should I add oak extract or something like that when I do waterchanges? I was thinking to have the water going in the tank in a container over night before the change, and add the oak extract in there if needed.

 

[dw1305]

Hi all,

Okay, thanks guys! I will continue with what I am doing then. What are your thoughts about pH btw? My tap water has a pH of 8.0, should I add oak extract or something like that when I do waterchanges? I was thinking to have the water going in the tank in a container over night before the change, and add the oak extract in there if needed.

It is difficult to say with the pH, the high reading could be caused by sodium hydroxide (NaOH), that has been added by the water company to protect pipes, or from a small amount of CaCO3 in the water. Alternatively there could be a huge reserve of carbonate buffering etc.

In the UK you can get analysis of your water from your water company, I'm not sure about elsewhere. If there was tap water in the tank where the bog wood lowered pH? It is likely that there isn't a huge reserve of buffering.

Do you have a conductivity meter (TDS meter)? they just tell you about the amount of ions in solution, but it gives you an idea.

cheers Darrel

 

[TuvaM]

I found some information on a website about waterquality. Water here is quite soft and acidic so they put something in it to raise pH to around 8. I measured Kh to be 0, so there isn't much, or any, buffering capacity in the water. I couldn't find anything about it on the website though. I don't have a TDS meter.

 

[TuvaM]

Update for today: nitrite is 0 mg/L and nitrate at 25 mg/L, pH is between 6.5 and 7.0 somewhere. Seems like it's safe for living creatures in there. There is just one thing that worries me a bit. Some of my plants seem to be withering. Some have holes, are turning yellow and some turn see-through. Could it be that I have plants which don't thrive in low pH? Or is it due to low Co2? I measured it to be <15 mg/L.

 

[dw1305]

Hi all,

I found some information on a website about waterquality. Water here is quite soft and acidic so they put something in it to raise pH to around 8. I measured Kh to be 0, so there isn't much, or any, buffering capacity in the water. I couldn't find anything about it on the website though. I don't have a TDS meter.

OK, that is a promising start for Apistogramma keeping.

The chemical added is almost certainly NaOH. It is a strong base (the OH- ion will accept an H+ ion) and all the OH- ions are in solution (there is no insoluble reserve or "buffer"). This means that you only need a very small amount of NaOH to raise the pH, which is why the water companies like it.

You can buffer the water (add some dKH) with a very small amount of potassium bicarbonate (KHCO3) or a small amount of "oyster shell chick grit" (CaCO3). Have a look at <"James' Planted Tank"> and <"Plants in the low KH aquarium"> for more detail.

Update for today: nitrite is 0 mg/L and nitrate at 25 mg/L, pH is between 6.5 and 7.0 somewhere. Seems like it's safe for living creatures in there. There is just one thing that worries me a bit. Some of my plants seem to be withering. Some have holes, are turning yellow and some turn see-through. Could it be that I have plants which don't thrive in low pH? Or is it due to low Co2? I measured it to be <15 mg/L.

It is possibly a nutrient deficiency, or it may be the plants adapting to the conditions in the tank (plants are grown commercially emersed). Looking at the photo you posted I'm now wondering if the plant near the coconut is <"Ophiopogon">? If it is Ophiopogon it won't grow submerged in the long term.

You won't have much CO2, you can't measure it very easily directly, but you can only get lots of CO2 by adding it. The equilibrium value for dissolved CO2 is less than 1 mg/L.(ppm).

Have a look at <"DwarfCichlid: Aquarium Plants"> <"Questions about SA Soft-water Planted Tank Setup"> & <"Duckweed Index">.

cheers Darrel

 

[TuvaM]

Thanks again Darrel.
The plant might be the one you are talking about, but I'm not sure. The guy I bought it from had no idea about the names, and there were no label on them. Probably not a good idea. I don't think it is nutrient deficiency as I added fertilizer to the substrate last week. Hopefully they will return to normal.

 

[TuvaM]

You can buffer the water (add some dKH) with a very small amount of potassium bicarbonate (KHCO3) or a small amount of "oyster shell chick grit" (CaCO3). Have a look at <"James' Planted Tank"> and <"Plants in the low KH aquarium"> for more detail.

cheers Darrel

Is it okay to use gh/kh+? That is about the only thing I can find in the online shops at least.

 

[dw1305]

Hi all,

The plant might be the one you are talking about, but I'm not sure. The guy I bought it from had no idea about the names, and there were no label on them.

If it is Ophiopogon it has really stiff leaves.

I don't think it is nutrient deficiency as I added fertilizer to the substrate last week. Hopefully they will return to normal.

You'll have to see what happens.

Is it okay to use gh/kh+? That is about the only thing I can find in the online shops at least.

Yes you can, and you only need to add a very small amount, but it is still an expensive option.

Potassium bicarbonate, calcium chloride and "Oyster shell chick grit" should be obtainable. The first two they sell for culinary purposes and the "chick grit" as a supplement for chicken keeping.

cheers Darrel

 

[TuvaM]

It's not Ophiopogon then, this one has soft leaves. I think it is Sagittatia Subulata. Compared it to one I saw at another fish store today.
I have ordered potassium bicarbonate from ebay. For some reason I worry about the customs, but hopefully it will be okay.

 

[TuvaM]

@dw1305 Should I turn off the O2 diffuser when the tank is "cycled"? Or when I get fish in?

 

[dw1305]

Hi all,

@dw1305 Should I turn off the O2 diffuser when the tank is "cycled"?

You can just leave it on.

High levels of dissolved oxygen are always a good thing. Once your plants are in active growth they are net oxygen producers, but even if you don't need the extra oxygen from the venturi normally it gives you extra capacity at night and if you have a water pollution incident (emergency chloramine dosing of your tap water, or an undiscovered dead fish).

It is often posted that you shouldn't have air stones etc. on planted tanks because it "drives the CO2 off", but that is wrong. When the plants are actively photosynthesising, greater gas exchange leads to higher CO2 levels.

This is my 60cm kitchen tank from front and top respectively, there are venturis on both the external Eheim 2224 and internal Eheim "Aquaball":

cheers Darrel

 

[TuvaM]

Alright, thanks Darrel! Soon there will be fish in my tank!

 

[dw1305]

Hi all,

Soon there will be fish in my tank!

No hurry, good things come to those who wait.

It is great having a tank that is empty, but planted and up and running. You have the great advantage of being able to wait until you find the fish you really want. I add some live food (Asellus, Crangonyx, Lumbriculus, Daphnia, Ostracods etc) cultures, and then hopefully when I add the fish they have some live food to help them acclimatize.

I usually have at least one tank planted and filtered, but empty, I can use it (at separate times) as fry grow-out tank, a quarantine tank, a source of microbial filter bacteria and, if I unexpectedly come upon some really unusual fish I can buy them without having to worry about where I'm going to house them.

cheers Darrel