Question on CO2, PH swings and shrimps

[aquaprawn]

Every day my PH swings from 7.3 to 6.7 due to CO2 injection.

8.15am - lights/CO2 ON. Air pump OFF (stops night aeration). PH is 7.2 or 7.3 at this time.
9.15 - 7.0
11.30 - 6.9
12.30 - 6.8
2.00pm - 6.7
2.15pm - lights/CO2 OFF - 6.7
3.30pm - 6.9
3.45pm - lights/CO2 ON
4.30pm - 6.8
5.30pm - 6.8
7.30pm - 6.7
7.45pm - lights/CO2 OFF -> Night aeration on. This blows bubbles into my tank from an airpump.
8.30pm - 6.8

Its a 3 footer community tank, moderate planted.
My setup is 11 months old, ADA soil is about 3 inches thick covering 70% of the area. 
I thought ADA should buffer PH to 6.8. My PH before CO2 is 7.3. I'm not sure if my PH pen needs calibration or its due to blowing bubbles into my tank (night aeration).
KH is 3, GH is 6

I keep Cherries, Blue Velvet, CRS/CBS, Tigers. Except for the CBS/CRS, all the shrimps are doing great and have been breeding.

For the CBS/CRS, a bit of a mixed success/failure story. They've been in there for about 5 months now.
Had a couple of deaths. Added 6 CBS 2 months ago - left one now (failure story). But that one recently got berried (success story).
For the CRS - maybe lost a handful, but generally the population only had a slight decline. They look healthy, but so far, none got berried.

I finally nailed it down to the PH swings that are affecting the more sensitive shrimps.

Is there any truth to this and is there anything I can do to mitigate this factor? I certainly cannot stop the CO2, neither isolate the CRS.

 

[ShrimpP]

pH swings might not be the main cause/issue, maybe it's just improper water parameters (higher pH, slightly higher KH) for the CRS/CBS. But I am sure the pH fluctuations, lower dissolved oxygen and higher concentrations of co2 don't help (each adds a bit more load/stress on livestock, but it's all accumulative).

Look at water parameters here

http://www.discobee.com/blogs/news/17030569-shrimp-water-parameters

Neocaridinas are pretty adaptable so they can breed in a wide range of parameters, but Caridinas are more sensitive and need params to be in their range.

Tigers are good in low 7's pH.

Look at all the water parameter preferences for each shrimp species (pH, KH, GH, Temperature, TDS). They all play a role, the more the water chemistry is out of their preference, the more likely they won't breed or do well/survive.

[aquaprawn]

Thank you. I'll add some more info on my water chemistry.
PH 6.7 to 7.3
KH3, GH6
TDS160
Temp: 77F-78.8F

Based on the parameters on the website you provided for :-
Crystal Red Shrimp Red Bee
PH: 6.2–6.6, KH: 0–2, GH: 4–6
TDS: 100–180, Water temp: 70-73F

But somehow I'm puzzled by these. Looking at another site the data is different:-
http://www.planetinverts.com/Crystal%20Red%20Shrimp.html

It says PH6.5-7.5. Temp 64-78F.

So which site do you follow?

[Mr. F]

Thank you. I'll add some more info on my water chemistry.

PH 6.7 to 7.3

KH3, GH6

TDS160

Temp: 77F-78.8F

Based on the parameters on the website you provided for :-

Crystal Red Shrimp Red Bee

PH: 6.2–6.6, KH: 0–2, GH: 4–6

TDS: 100–180, Water temp: 70-73F

But somehow I'm puzzled by these. Looking at another site the data is different:-

http://www.planetinverts.com/Crystal%20Red%20Shrimp.html

It says PH6.5-7.5. Temp 64-78F.

So which site do you follow?

That's way too hot for crystals!!! They will be cooked. Get it down to 68-72! Neos will be good.

KH no higher than 2, preferably 0, but having CRS with neos 1-2.

GH is a little more forgiving as long as you keep your TDS low, like 100's. You seem okay with TDS, but I'd shoot for GH 4 (maybe 5) as that seems to be a nice overlap for the CRS/CBS and neos.

Also, given than you have neos, the pH should be on the high range of crystals which includes the low range of neos, for the most part. I'd probably shoot for 6.5-6.7

[Maurice]

Hi Aquaprawn

I assume you use tap water for doing w/c? This would have depleted your buffering from the aquasoil already by now, so not the best for CRS/CBS 

also like you said the fluctuating in Ph is also not the best for them with co2, as they prefer constant, stable water parameters.

i don't say you can't keep them in a co2 planted tank, it just gets a little tricky

 

cant you maybe setup a dedicated low light, non co2 tank for the caridinas?

[aquaprawn]

Thank you all for the replies. I appreciate it very much. I think I get the point. I need to adjust my water parameters to lower GH/KH and further lower the temp. I'll be investing in an RO unit because my tap water is too hard. And I'll lower the temp on my chiller.

I can't do anything about the fluctuating PH because I need to keep injecting CO2. Have been thinking about setting up a low tech tank just for shrimps, but that's in the pipeline.

[gillznglass]

I don't envy you having to balance those water parameters. That is tough. With low or no kh, Co2 may cause some huge pH swings. It would be nice if there was a Co2 sensor that would regulate Co2 to keep a target pH. May help not to dose at night.

[aquaprawn]

Frankly speaking guys, I'll give you my take on this. High grade shrimp and CO2 don't mix. I find it frustrating that you can either have a nice high tech tank, or nice shrimps, but not both together. By high grade I mean CRS S and above. The higher the grade, the more sensitive.

I've heard of a few who managed to find the sweet spot of balancing CO2, plants, and keeping shrimps healthy. But that is mostly a hit-and-miss story and many will say it depends on the shrimps ability to adapt, and many will die but you'll be lucky that some will survive. If you keep adding shrimps, eventually you'll be lucky enough to have a sustainable population.

Then there's the odd story where you have a dead low grade CRS A, and a berried high grade CBS SS grade (happened to me). This was amongst five dead CBS, and another dead Tiger - I attribute my berried CBS as "I got lucky she's a survivor and managed to adapt".

Because I've seen CO2 entering my tank, and I can see all the plants bubbling with photosynthesis - and I know there's CO2 in there, and its this CO2 that's killing my CRS. If I'm willing to shut off my CO2, the CRS shrimp population will explode.

As for the Neos, and Tigers, they are doing well amidst the CO2. They're a tough bunch because unlike the higher grades, they didn't go through so much selective breeding that weakened it.

For me, I'm going to try to reduce the CO2 by just a notch. If the CRS still don't make it, I may refocus on the Neo line instead. There are plenty too from Rili shrimp to BV, but admittedly the Caridina line are much more beautiful.

However I have no joy in looking at beautiful shrimps in an ugly tank (ie low tech tank).

As one person said, "Either high grade or high tech. If both, be prepared to keep adding shrimps."