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Beginning of algaes after doubling light

Angelo Kostakis

Seedling
Joined
2 Dec 2014
Messages
8
Hi all,

I have an aquarium of 200 liters and a height of 65cm.
Light = 4 x T5 28W.

I use the estimative index for natrium, PO4 and potassium.
For the Micro elements i use Easy life Profito as well as Easy life ferro.

I change every week 50 procent of my water.
This morning i tested the water before my lights went on and i had these values:

KH = 12
PH = 6,5
NO3 = 25mg/l
PO4 = 1,5mg/l
Potassium = 20mg/l
Fe = 0,5mg/L

I have a lot of brown algae on my substrate but it can be because i have small stones in my substrate that contain a lot of silicate

Now blue algae begins to appear so i will do a total black out next week.

I also have green algae, since 2 weeks. Before i had 2x T5 and now 4 x T5 so maybe because of to much light?

Possible solutions ?

the Moss and riccia start to pearl but the Monte carlo doesn't grow very good. I have a lot of new leaves but they stay small and after a while they die.


Can someone help me please ?
Tanks a lot

Greets
Angelo
 
yes i have pressurised CO2 and i also use a aquamedic 1000 reactor to fully solve the CO2
 
That's great but yeah the algae means you have too much light for the amount of CO2 you are adding. So decrease the light and look at your CO2.

From the moment CO2 comes on you need to get about a 1 point drop in pH before the lights come on (2 hours or so). If you have good surface rippling, the pH will settle at more or less the same level until it is turned off. This way it shouldn't increase to dangerous levels for fish/shrimp. Nonetheless you've really gotta have some time to increase the CO2 and watch the pH and fish behaviour.

P
 
What about the KH? With that amount of KH how can he drop down 1 PPm in the PH?
For instance in my case:. I have a Kh of 10. Before my lights went on i have a PH of 7.6 and no matter how much ammount do i inject in the 2 howrs before the lights went on, i can never get the target of 6.6 on PH .
Only 6.8... and i think that it´s a result of the KH value. The KH works as a valve. At a certain point it doesn´t matter the ammount of Co2 you are injecting cause you´ll never get a drop of 1 ppm in the PH cause of that valve the KH is itself.

So, he will have this issue and i don´t think he´s gonna get a 1 ppm drop down in the PH.. so propably he´ll have to reajust the light. Maybe put it in higher level and not so close to the water.

Don´t you think so?

Best regards
 
And other thing to he should pay attention..
Another example:
(i have a photoperiod of 8 hours)
If i do regulate the Co2 to inject an ammount in order to drop the Ph from 7.6 to 6.8 in that couple of hours before the lights went on after 4 hours (half of the photoperiod) the fish are all at the top of the water trying to breath... so i can´t (probably he will not to) continue to pump these amount od co2.. to all eight hours.. the fish can not stand it.!

So i had to decrease the amount of Co2 in those couple of hours and let it get the drop down in the PH further before along the the eight hours photoperiod. By the end of the photoperiod i got 6.8 of Ph.. This is the only way my fish can handle it.

So.. what now?
I could drop KH. But how? With "Amtra Torf".but the water will look like "tea".. :(
This is a damn issue... im struggling in with ít for quit a while..
To damn hard to balance Co2 and Light with this levels of Kh..
 
And things get worst .. prety nasty if you don´t have a GREAT CO2 diffuser or great diffusion with that reactor. . Cause if you don´t, most of the co2 you are injecting is not being absorved.
In my case i had to buy a ADA 40 mm to guarantee that BREAKS the bubbles almost to look like dust in the tank...otherwise.. "Houston! I have a problem!" :)
It improves a lot cause i achieve the 6.8 PH more faster than with other Diffusers mas it stoped there.. never reach 6.6. cause of the KH. (i think)
 
I think with higher KH you can get away with a smaller pH decrease. My KH is only 4 and I had to add something to make it that high. I get just over a 1 pH decrease in 2 hours and it stays that way until the CO2 goes off 6 hours later. I think the pH can remain stable because I have lots of surface agitation from a surface skimmer and a Koralia flow pump.

Watching my fish, they are often at the surface in the last few hours of CO2 injection, even though the pH has been stable. I think that where I place the pH meter is an area of low CO2 so I don't get a representative reading. I will reduce the CO2 a little and it should still be OK for plants and fish.

I use an Up in-line atomiser which creates a mist all over the aquarium which doesn't look that nice. I'm also not sure if the fish find the low pH a problem or just that they don't like all the tiny bubbles. In any case if you really have too much CO2 the fish and shrimp react more seriously e.g the shrimp jump out or lie still at the bottom.

I have only tried in-tank diffusers for a little while and I could never get good CO2 levels with them. So much seems to be wasted.

So overall, if you reduce your light it can only help as the plants will then not need so much CO2...

P
 
Paulo, why do you want for your pH do drop to 6.8 if it causes your fish to have problems? With KH 10 and pH 6.8 you must have around 50 ppm CO2 at 25°C which is way too high. At pH 7.0 you would have 30 ppm CO2, and at pH 7.2 you would have 20 ppm CO2. I think no aquatic plants need more then 20 ppm CO2 for good and healthy growth, although at low pH (around 6) most green/red algae and cyanobacteria are inhibited or die. So keeping low pH may be good for eliminating some troublesome algae species, but for plants such a high CO2 levels are not needed.

You can look at the tank of my friend who has around 15 ppm CO2 in his high light tank (the values on the picture are for light intensity measured in µmol PAR):
mereni_blau_4x24w_jn.jpg

Do you still believe the myth that high light (100-500 µmol PAR) and low CO2 (15 ppm) mean algae?
 
Last edited by a moderator:
Hello Ardjuna,

Thanks for replying. I simple did that a few months ago according to what was sugested here in this forum by a member. A respectable member. And what i´ve said upwords it was a description of what happens. They told me exactly as Pepedopoulos said to Angelo:

From the moment CO2 comes on you need to get about a 1 point drop in pH before the lights come on (2 hours or so).

And in my case happen what i described.

Now.. tell me please how do you find the figures you mentioned?
Cause i´ve seen a lot of tables (KH versus PH = Co2 levels) and i couldn´t find the numbers you reffering.

Do you agree if i use this table ?

2a65ts0.gif
 
For what i can see in this table i should regulate the injection till get 7.0 or 7.1 of Ph with my KH in 10.
Isn´t that so?

Do you find this table to Angelo follow to? With his 12 Kh he shold achiev 7.1 or 7.2 of Ph.
 
Guys,

I don't think KH/pH tables work when you just take one 'snapshot' of water and assume that the pH is only due to CO2 and carbonates (KH).

If you observe the changes in pH as you add CO2 over the course of a few hours, you then know that the pH decrease is 99.9% due to the CO2 added and nothing else.

My KH is 4 and with CO2 injection, the pH decreases from ~6.7 to to ~5.6.

According to that table above, even at pH6, I have 120PPM CO2!

Even before I've turned the CO2 on, according to that table I've got 30PPM CO2 at pH6.7! That just isn't possible! At pH6.7 the CO2 in my case is at equilibrium with atmospheric CO2 and that isn't enough to grow semi-aquatic plants!


P
 
The data in the table above are based on the assumption that all alkalinity (mistakenly refered to as "KH") is made by bicarbonates (HCO3). This may not be true in all tanks, although in most tanks this assumption is probably correct. Alkalinity could be raised not only by HCO3 [NaHCO3, KHCO3, Ca(HCO3)2, Mg(HCO3)2 etc.], but also by fulvic acids, citric acid and some other acids. If this is the case in your tank, then the pH-alkalinity-CO2 table will give you wrong (usually higher) numbers. The best (easy) way to know how much CO2 do you have in your tank, is to use this table together with a dropchecker. Still, you need some quality pH meter and quality KH test to give you reliable numbers. So to answer your question (whether you should try to aim for pH 7.0), I would do the same. I don't see any good on lowering your pH to 6.8 by supplying some extremely high CO2 levels. As I said, I'm convinced that for most aquatic plants 15-20 ppm CO2 is more then enough. I know that Tom Barr or Clive (ceg4048) are recommending much higher CO2 levels (for example, Tom Barr has 50-70 ppm CO2 in his main tank), but I don't see any good on these extremes. As you can see from the beautiful tank of my friend, even with 15 ppm CO2 you can have a nice growing plants and tank without visible algae. Also, I have quite a number of scientific papers which say that for most aquatic plants the CO2 saturation point is somewhere around 20-40 ppm, so at this concentration the plants will grow at maximum rate. But I don't want them to grow at maximum speed. I can make do with 80-90% ... for which 10-15 ppm CO2 is more then sufficient.
 
Ardjuna,

I live in Prague and you're welcome to visit and test my aquarium(s). I don't consider myself an expert but since re-starting my current main tank, I'm using low light (20-30 PAR according to a Seneye), EI ferts and high CO2 (according to my fish, I've reduced it a bit since). So far I've got healthy plants, steady growth and no algae. It's the best start I've had for any set up.

I don't care who is wrong or right. I'm also well aware that there have been and still are many myths about fishkeeping (e.g Old Tank Syndrome and pH crashes, nutrients = algae). In my experience the closer I manage to replicate what Tom Barr et al recommend, the better I do. I'm not gonna risk upsetting my current set up by turning up the light right now.

Nonetheless, I really think we need more people like you who are ready and able to do some scientific tests and share the results, whatever they may be. It's a damn shame that manufacturers who benefit from hobbyists' money aren't doing or supporting more research.

P
 
As I said, I'm convinced that for most aquatic plants 15-20 ppm CO2 is more then enough. I know that Tom Barr or Clive (ceg4048) are recommending much higher CO2 levels (for example, Tom Barr has 50-70 ppm CO2 in his main tank), but I don't see any good on these extremes
The reason you don't see any benefit is because you are either miscalculating something, misreading something or not taking some other factor into account.

Do you still believe the myth that high light (100-500 µmol PAR) and low CO2 (15 ppm) mean algae?
Yes. Clearly, you have misunderstood the fundamental argument. High CO2 does not just mean that you are injecting high levels of CO2. High CO2 is within the context of high uptake of CO2. If flow and distribution are good, if timing of the injection is good, if temperatures are not high and if plants are clean and in good health then the uptake rate of a lesser injected tank can be higher than that of a tank with greater injection rate, but which has poor distribution and so forth. We see this all the time where the injection rate is undermined by poor flow and distribution and poor timing of the injection. Additionally, there is a wide range of acceptable CO2 values and if plants are healthy they can adapt to stress.

Additionally, the CO2 in a tank is never homogeneous, and is never static. At different locations in the tank the CO2 will always be different. It c an be 10X lower within the plant beds than at the surface or mid level. If you have a CO2 meter then it is likely that a correct CO2 concentration value can be obtained. If the values are being calculated from charts or graphs then it is only a general estimate.

It's folly to draw a conclusion based on a single parameter when it has been clearly demonstrated that there are many factors involved in a behavior.


most green/red algae and cyanobacteria are inhibited or die. So keeping low pH may be good for eliminating some troublesome algae species, but for plants such a high CO2 levels are not needed.
This is not true at all. Algae do not care how much the pH is and they do not care how much CO2 is in the water. I can easily induce algal blooms at any pH and at any CO2 level.

This is another fundamental misinterpretation of the facts and data. IN an tank, algae respond and change their behavior as a result of the presence of other organisms. The presence of plants affects the behavior of algae and the presence of algae affect the behavior of plants. There is a predatory relationship between algae and plants and blooms are related to the health of the plants. It never matters what the CO2 or nutrient levels are if the plants are failing in health due to an inability to take advantage of available CO2 and nutrients.

Cheers,
 
Additionally, the CO2 in a tank is never homogeneous, and is never static
This makes pH profiles problematic if like me you poke a pH meter in the surface water somewhere. I've found that pushing the pH meter a little deeper shows a lower pH and that pH is also lower if I place the meter directly in the water outflow (even when in-line CO2 injection is off).

Recently, I've noticed my fish staying at surface (gasping a little) during the last few hours of CO2 injection, even though my readings from the surface are stable. If I have OK CO2 distribution, where should I expect the most CO2- higher or lower in the water column?

Thanks,

P
 
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