Spooked Angels = High CO2?

[sfarkhan]

Gonna ask the experts because you've all used CO2 way more than I have.

I posted this on the planted tank with limited response.

I woke up Monday morning and my Angelfish were hiding in the back. They used to come out as soon as I come to the tank but now they bolt and hide. They have never acted timid before - Normally if I'm near the tank, they are pressed against the glass begging for food.

When they do come out, they come to the surface and gulp air 1/2 the time.

There are other fish: oto cats, cory cats, a hillstream loach, and a school of 10 cardinals that don't seem to be phased by my presence...

I removed the old tank's Aquaclear filter on Sunday. I was using it to help cycle this tank. The primary, a Fluval 406, is still running. The water conditions were tested and are normal.

They were fine the rest of the afternoon/evening after I removed the Aquaclear. I wonder if they were used to the surface turbulence of the Aquaclear and now they can feel/hear the vibrations my feet make...

One Angel nearly jumped out of the tank when I approached...

Or the CO2 is dialed up too high and they are being gassed.

Update
I dialed down the CO2 from 2.5 to 2 bps - I also moved the lily pipe output to the water's surface so it churns it a tiny amount.

Today, 2 days later, the Koi Angel is not gulping air and ate food and didn't act as timid. The zebra lace pair are still scared of their own shadows and are gulping O2 half the time. The other half they are picking the bottom.

The other fish in the tank are still unfazed.

Any suggestions?

[krisw]

Shahriar, yes, you were likely stressing the Angels with too high a concentration of CO2. Angels are big fish, and in my experience, big fish often have higher oxygen requirements that the smaller ones. I've had a couple CO2 dumps where all of the largest fish in the tank died, but the smaller ones muscled through it. As a guideline, make sure that the pH drop from CO2 is no more than 1 degree from your water's natural pH. (Measure before CO2 kicks on in the morning, and after it's been running for awhile, and subtract.)

That said, no matter the readings, if your fish are stressed, dial it back until they're happy. Killing plants is one thing, but it sucks to kill fish.

[jweis]

After killing lots of shrimp , I have become a huge fan of PH monitors/controllers. Now it doesn't really matter what I have my regulator set to, since the monitor/controller makes sure I don't overdo it.

Before I was relying on drop checkers, and I learned an important lesson -- they don't work (at least for me).

[krisw]

How often do you need to change out/re-calibrate your PH controllers?

[jweis]

How often do you need to change out/re-calibrate your PH controllers?

The instructions say to recalibrate it once a month. I took mine out once after about 6 months and it didn't need to be recalibrated. I have one in-line so it is more of pain to take out and recalibrate. The one in the other than just hides behind some plants and it is easy to take out and recalibrate (but I am lazy in that regard).

The actualy recalibration is very easy. You just stick it in a glass of solution and turn a little knob until it reads 7.0.

[sfarkhan]

Shahriar, yes, you were likely stressing the Angels with too high a concentration of CO2. Angels are big fish, and in my experience, big fish often have higher oxygen requirements that the smaller ones. I've had a couple CO2 dumps where all of the largest fish in the tank died, but the smaller ones muscled through it. As a guideline, make sure that the pH drop from CO2 is no more than 1 degree from your water's natural pH. (Measure before CO2 kicks on in the morning, and after it's been running for awhile, and subtract.)

That said, no matter the readings, if your fish are stressed, dial it back until they're happy. Killing plants is one thing, but it sucks to kill fish.

Understood. Thanks for the advice. Lesson learned.

I started at 2.5 bps, but removing the Aquaclear may have removed suface agitation which kept enough O2 to keep them happy. I dialed it back to 2bps and they livend up a bit, but not the greedy angels I'm used to.

I also have to move the intake lily pipe to the same side as the exhaust lily pipe - That may make a difference as it churns the tank a bit more.

Lastly, if that doesn't help, I'll dial it back to 1.5bps and see how they act.

I did a PH/KH calculation using Rex Grigg's chart: http://www.rexgrigg.com/Algae1.html
Did I mention DC water is fantastic
KH: 2
pH: 6.2
CO2: ~37ppm

The drop checker is green. I will move it to the other side. I had two - I removed it when I removed the AquaClear. I should have left it for another day - it was a lighter color with the AquaClear running next to it. It would have warned me if I left it on longer.

[sfarkhan]

After killing lots of shrimp , I have become a huge fan of PH monitors/controllers. Now it doesn't really matter what I have my regulator set to, since the monitor/controller makes sure I don't overdo it.

Before I was relying on drop checkers, and I learned an important lesson -- they don't work (at least for me).

What is this "PH monitor" you speak of?
I didn't think I needed one - They are 'spensive

[jweis]

After killing lots of shrimp , I have become a huge fan of PH monitors/controllers. Now it doesn't really matter what I have my regulator set to, since the monitor/controller makes sure I don't overdo it.

Before I was relying on drop checkers, and I learned an important lesson -- they don't work (at least for me).

What is this "PH monitor" you speak of?
I didn't think I needed one - They are 'spensive

I type I have runs about $75. I bought mine from aquariumplants.com, but other places sell them too. I decided I didn't want to keep killing shrimp. Just a little too much CO2 and one can easily kill critters. I also like not worrying if I need more or less CO2 after added or removing a significant amount of plant material.

http://www.aquariumplants.com/Milwaukee ... l00311.htm

[sfarkhan]

Ok, not too expensive, I will look into one - How quickly does it take a reading?

I moved the input/output to the same side. I haven't dialed down the CO2 more because I want to see if this makes a difference.

So far the Angels are all out swimming around as usual, no gulping air. I haven't walked up to the tank, I'll give them till tomorrow to adjust.

[jweis]

Ok, not too expensive, I will look into one - How quickly does it take a reading?

I moved the input/output to the same side. I haven't dialed down the CO2 more because I want to see if this makes a difference.

So far the Angels are all out swimming around as usual, no gulping air. I haven't walked up to the tank, I'll give them till tomorrow to adjust.

The reading just takes a second and it displays the reading continuosly. I found once I accidentally put too much CO2 in my tank the fish/shrimp never fully recovered and died within a week. I will keep my fingers crossed that doesn't happen to you.