[funkyfish88]

Need some guidance. Tank started to experience 1 CRS death about 1 or 2 days about 2 wks ago. Been setup since May 2011, ADA Amazonia soil.

Parameters:
temp: ~70.4F - 72.4F
pH: 6.4
ammonia: 0
nitrate: 0
nitrite: 0
KH: 4dH (71.6ppm)
GH: 8 (143.2 ppm)
all test done using API liquid
Pressurized CO2 timed with lights & airstone: 3 hrs during the day, 4.5 hrs during the evening (off by 5:30p); drop checker blue-green, ~2 bps;

Other fauna: 50+ RCS, 2 threadfin rainbow, 1 long finned albino pleco, 1 otto, 1 Amano; No deaths nor gasping at surface;

Behavior of CRS, seemed lethargic, hiding in moss;

Trying to understand if there are physical characteristics of CO2 poisioning for shrimp (besides death). None have shown gasping at surface.

Right now I have stop injecting CO2, but kept airstone at 24/7 and have done a 25% WC per the advice of MORDALPHUS - thanks so much for your help.

Would like to see if anyone else might have some insights on this. I really do not want to tear down my CO2 system just yet.

Thanks everyone for any expertise or opinions.

 

[HolyAngel]

Kh and gh are a bit high.. Ideally you want them no more then half what they are right now.

 

[bsmith]

If you are using a 4dkh solution in your drop checker and its only turning blue/green I highly doubt that its the problem. Holyangel is correct. Your water should be a bit softer to be ideal for CRS. I also find it strange that your nitrates are at 0. A properly cycled tank should have a nitrate reading between 5-15.

 

[RandomMan]

With CO2 poisoning, the shrimp will fall over and lie on their side or with their feet in the air but still alive (at least for a while). And it will affect pretty much all of your shrimp at the same time, not just one.

Saw this happen at a LFS where one of the new guys after putting some new plants in a show tank turned up the CO2 and stopped paying attention. I caught it while most were still alive, but flopped on their side. Not sure how many survived in the end.

 

[funkyfish88]

Thanks everyone for your insights.

With the recommendation of Mordalphus I turned off the CO2 yesterday, did a 25% cold WC yesterday as well as one this morning. This morning, I noticed the CRS are all out (from hiding in the moss) and very active. The drop checker is currently blue.

When I had the CO2 (Azoo regulator w/ solenoid)running, did notice that when the CO2 initially goes on (in the morning), it seem to purge thru system and release a larger amt of gas, then would back down to the normal 2 bps. I do not have it set up where the lights go on prior to the gas and off before. They are both on the same timer. Maybe this will help if I vary the time in which the gas & light goes on/off?

As far as death, I did observe one where the shrimp (noticed the coloring was off) was upside down on a leave & did a free fall to the ground. It did move, but rather slowly toward the moss. I, then, took a "poker" to see if it would move, but it curled inwards and went "stiff". Again, others in the tank were very lethargic and just hanging in the java moss.

Trying to come to some conclusion on whether the WC or the CO2 off resolved the problem. Or maybe both.

I really want to run the CO2, but obviously also do not want to see more CRS deaths due to it.

 

[bsmith]

I always tell people that if you want a vibrant thriving CRS colony you should not have co2 on the tank. They are just too sensitive and this adds yet another problem they have to deal with.

 

[HolyAngel]

yeah definitely ^^

Im still not sure its co2 though.. i'd wager the kh/gh and/or something else in the water..

Are you positive you did the nitrate test correctly? you shook both bottles for about a minute before use? and shook the test tube for 30 seconds? could try biochemzorb or purigen in the filter to clear out anything we can't test for..

 

[funkyfish88]

Alright, I just retested the nitrate. Reading looks more like 5 ppm rather than 0. I placed the tube against the white area to the right of the color chart to get the reading.

Checked out the tank, and the CRS are out and scavenging.

Might have to start a new tank for the CRS or sell the CO2 setup :icon_sad:.

Besides RCS, any other shrimps that are tolerant of CO2 (of course, within reason).

Thanks again everyone!