Need Help With Stressed Amanos w/ CO2

[somail]

Hi,

I understand Amanos to be pretty hearty shrimp, but I am starting to have a difficult time keeping them. I believe it is due to my CO2 injection. I am trying to grow HC Cuba and therefore I recently started an uptick in my CO2 injection. The fish (cherry carbs, various tetras and ottos) are all fine with no signs of stress, but the Amanos are acting odd.

The best description I can provide is that around the same time every day (1 -3pm) there is a high chance that an Amano will dart to the surface then fall back upside-down, almost like it has been shocked or poisoned. It turns clear brown to bright blue in a manner of seconds and just twitches for a number of minutes. The shrimp will usually recover (after it acts drunk for a while), but if he falls in the wrong spot there is a chance a fish could find an easy snack (which is my main concern). If the fish ignore the shrimp, it will normally make a full recover in about 30 minutes. The odd thing is that it happens very quickly like something touched the shrimp causing it to go into shock. Most of the other shrimp are grazing and it is usually just one or two shrimp that decide to go crazy on the particular day. It is normally within the same time frame, thus the reason I think it is the CO2. The only other hypothesis I have is the shrimp are literally being shocked 😵. I live in a dry climate and every time I touch the water surface I will get a light shock. Given the shrimp already live in the water I highly doubt this is even possible.

Here are my water specs:

50 Gal
Ammonia = 0.25ppm
Nitrite= 0ppm
Nitrate <40ppm
50% water change 2x week
RO water, which I do not remineralize very often: I have Seiryu Stones (or whatever passes for them these days) as the main hardscape and it leeches minerals quite a bit. After a 50% change I will be at 120 TDS, 6KH/7GH with no additives. The KH and GH will increase about a 0.5KH/0.5GH a day until the next water change.

Below are my PH readings based on my Co2 and photo period schedule. Note that the PH will climb daily due to the rocks leeching, but my current PH drop seems to be 1.2 in all cases. This table was recorded when the water was at 6 KH. Note that I have noticed the same behavior if my starting PH start higher at 8 and the low end of the drop is 6.8 (versus the 6.4 below).



Given that my PH range is reasonable (e.g. 1 - 1.2 drop) and the low end of the PH s still near the Amano's comfort level, I am not sure why this is happening. Many people use Amanos with a 1PH drop and so it makes me think I am missing something in my water chemistry.

I appreciate any help or advice.

 

[ceg4048]

Hi,
It would probably be wise to back the injection rate off a bit and review your injection method as well as flow/distribution. It should not require 5 hours to saturate the water with the gas. That's a really long time considering you really only need about 5 hours of gas in total. Could you clarify how you distribute, flow rate, injection method?

Cheers,

 

[somail]

Thanks for the reply. Injection right now is through a DIY Cerges reactor with the outflow via a standard Lilly pipe. I am taking the PH measurement from the water collected at the top of the tank coming out of the little pipe (not sure if that matters). I believe the flow rate is good, but other than looking I can't really tell. It is a iwagumi setup with a single large rock in the middle. I attached a pic so you can see the setup and you can probably guess the flow from it. Filtration is ran off of a Jebao DCP-5000 @ 70%. From previous measurements my flow rate should be in the 5-6x turnover rate.

 

[ceg4048]

Injection right now is through a DIY Cerges reactor with the outflow via a standard Lilly pipe. I am taking the PH measurement from the water collected at the top of the tank coming out of the little pipe (not sure if that matters). I believe the flow rate is good, but other than looking I can't really tell. It is a iwagumi setup with a single large rock in the middle. I attached a pic so you can see the setup and you can probably guess the flow from it. Filtration is ran off of a Jebao DCP-5000 @ 70%. From previous measurements my flow rate should be in the 5-6x turnover rate.

Hi,
Well I'm not sure taking a direct reading from the pipe is the best. That just tells you what's in the pipe, not necessarily what's in the tank, where the plants are. Even so, that would have given an optimistic reading and 5 hours to drop the ph is beyond inefficient. I'm not familiar with the Jebao. Is that a DC pump and is the 5000 the flow rate in liters per hour?

Anyway although the behavior of the shrimp seems to indicate CO2 distress try to confirm by shutting down lights and CO2 and see if the behavior changes. Shrimp are more susceptible to CO2 poisoning than fish are.

Cheers,

 

[ceg4048]

Err...what the heck happened? Half your post disappeared? Was I just dreaming about your pump and sleep-typed or was there a glitch in The Matrix?

 

[X3NiTH]

The only other hypothesis I have is the shrimp are literally being shocked 😵. I live in a dry climate and every time I touch the water surface I will get a light shock.

If you have access to a multimeter you can check whether the tank is grounded (likely) and that there is no stray current detected (indicates a piece of equipment is faulty and is an electrocution hazard), stray voltage is okay as long as it’s low.

I would back off your co2 peak pH to 6.8 as a precaution, your co2 atmospheric equilibrium profile for your KH is nearer pH7.8-8.

You can force an Equilibrium Profile out of a water sample by bottling the sample and shaking it vigorously to expel the co2 and periodically unscrewing the lid and exposing the sample to fresh air for a few rounds (400ppm external atmosphere, indoor spaces can have a much higher co2 ppm count depending on the ventilation).

🙂

 

[Kezzab]

What's going on with the skimmer head?

 

[Ivan Stoyanov]

Hi, my water is like your around kh6 and when my ph drop under 6.5 ph the fauna start to be upset. They are little better with a lot surface agitation, but you will lose a lot co2.
Ceg, what you mean only 5 hours, during photo period or total?

 

[somail]

Err...what the heck happened? Half your post disappeared? Was I just dreaming about your pump and sleep-typed or was there a glitch in The Matrix?

Probably my fault, I was editing my post and I do not think it updated right. I do have that pump. It is 1450gph / 5500lph. I was hesitant on it originally since I always used Eheim, but I really like it thus far (~6 month of usage).

If you have access to a multimeter you can check whether the tank is grounded (likely) and that there is no stray current detected (indicates a piece of equipment is faulty and is an electrocution hazard), stray voltage is okay as long as it’s low.

I would back off your co2 peak pH to 6.8 as a precaution, your co2 atmospheric equilibrium profile for your KH is nearer pH7.8-8.

You can force an Equilibrium Profile out of a water sample by bottling the sample and shaking it vigorously to expel the co2 and periodically unscrewing the lid and exposing the sample to fresh air for a few rounds (400ppm external atmosphere, indoor spaces can have a much higher co2 ppm count depending on the ventilation).

🙂

I have actually left water out over night to get to equilibrium (I think that is the same thing you are talking about). The conclusion was 8.1ph. That test is what prompted me to do the hourly PH measures in my original post. 8.1 -> 6.8 (or 6.4) is probably too much of a drop. But I really didn't see much god result with the HC at 7.0 ph. Based on X3Nith and ceg4048's advice I have made the following adjustments: Backed off my CO2 by 25%, lowered the light to adjust and I also increased the flow rate of the pump. I'll take a PH reading later today to see where I end up.

I think ceg4048 might be on to something in regard to the flow but other than one giant rock I do not have much restriction on where the water goes. Maybe the lily pipe isn't an ideal shape or I need to change where it is pointed? The one interesting thing is that if a shrimp does get stressed it will happen in the lower right part of the tank near the drop checker. That could be a coincidence, but I have yet to see a shrimp have issues in the top left area of the tank.

Hi, my water is like your around kh6 and when my ph drop under 6.5 ph the fauna start to be upset. They are little better with a lot surface agitation, but you will lose a lot co2.
Ceg, what you mean only 5 hours, during photo period or total?

I think he means the 1PH drop should happen within two hours, prior to the photo period turning on and then stay stable for the day. Right now I am dropping too slowly. This is an issue but I haven't been able to figure out how to get that drop in time (other than starting much earlier with the Co2 or gassing my shrimp).

Do you use a drop checker in your tank? I am curious to know the color when you are at 6.5. As you can see in my original pic, mine is very yellow, almost clear.

What's going on with the skimmer head?

I use a cut up mesh "biobag" to cover the skimmer to prevent the shrimp from climbing down (doesn't restrict water flow and skimmer still bobs up and down). It turns brown after a while. Due to the CO2 issue some of my HC Cuba is floating up and catching on the skimmer. It looks much worse than it is and doesn't seem to be impacting water flow down the skimmer.

 

[Ivan Stoyanov]

My is yellow but with some green in there, not exactly pure yellow.
You will be able to drop faster with more surface agitation and more injection rate.

 

[somail]

Quick update. I went through the day with the lower CO2 and no issues with the shrimp. Most of them didn't even come out of hiding today, which tells me I was greatly under estimating their stress level. PH reached a low of 7.0 which was probably a 0.8ish drop for the day. Drop checker yellow with a very small hint of green. I will probably ease it back up over the next couple of days to find that sweet spot, but likely don't have much more room. Once I get that dialed in I will probably make a thread on my injection. ceg4048 was right, I should hit my 1ph drop sooner and cranking the CO2 probably isn't an option due to the shrimp. Or I just dump the HC Cuba switch to Monte Carlo and call it a day.....

 

[ceg4048]

Ceg, what you mean only 5 hours, during photo period or total?

Hello Ivan,
Plants really do not use CO2 all day. They collect what they can for a little of half the day and then start to close down this CO2 acquisition. So in an 8-10 hour day only the first 4-5 is when we really need awesome CO2. After that you can give your animals a break and turn off the gas. The majority of folks do not pay attention to this issue. It's when the lights go on in the morning that is critical. That's why we suggest to turn the gas on and to get the CO2 concentration up to maximum and THEN turn the lights on. Then the plants have immediate access to CO2 and can start and rev their engines. After midday they really don't care that much. I see a lot of cases where the hobbyist has their pH at the minimum (CO2 at it's maximum) far into the photoperiod, when it's almost useless and yet still suffer CO2 shortfall while the fish start to vomit. Many CO2 problems therefore actually are happening at the beginning of the day and they do not realize it.

Cheers,

 

[ceg4048]

Or I just dump the HC Cuba switch to Monte Carlo and call it a day.....

Well, I mean, these plants are labeled in many shops as "high light" plants, which is not really the case. They are actually high CO2 plants and high light forces the need in plants for high CO2. If you avoid over the top lighting then growth will be slow but steady.
Fix your CO2/flow/distribution mate and you'll be okay.

Cheers,