# Unexplained CRS deaths



## modster (Jun 16, 2007)

I am not new to shrimp keeping, but I can't stop my new shrimps from dying. I have had an active breeding colony of grade A/S CRS for 6 years without any problems. Earlier this year, I decided to start another shrimp tank but with SSS grade CRS. The two tanks pretty much have the same setup. The problem is I have been losing about 1-2 shrimps per month in the high grade tank. I can not explain this at all. The shrimps always seem listless. All the common parameters are okay (0 ammonia, 0 nitrite, ~5 nitrate). A 20% water change would make the shrimps active for a day or two and then they would go back to the non-active state. Things have really gone south this week. I found 3 dead shrimps yesterday (one was berried too ) and there are only two CRS left in that tank. I also have some cherries in that tank and they seems to be doing fine. Any idea why this is happening?


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## Fishfur (Oct 17, 2013)

What are the other parameters ? If cherries are ok but crystals are not, it makes me think something might be off with the GH, perhaps ? Metals or other toxins would affect all shrimp, so it's not that. Are the substrates the same ?


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## modster (Jun 16, 2007)

My substrate is a thin layer of aquasoil. I don't test GH directly because for the life of me, I can't tell when the color change. I know my GH is in range by starting with RO and measure TDS. I used to use RO + equilibrium and more recently RO + mosura mineral plus. Anyway, my establish tank is experiencing the same problem now :-( I got a few theories about what is happening. 

1. There is some kind of infection going on. Not sure how likely this is. I have always been mindful about not cross contaminating the two shrimp tanks. Anyway, there is really nothing much I can do about this.

2. I started using mosura product about 2 months ago (bio plus, tonic pro, gravidas and their crs food). Not accusing them of anything... Just one of the changes recently. I am going to stop using them and see how it turns out.

3. Each tank has a pvc pipe filled with aquarium gravel to anchor plants. I have been using this for a while. The caps were not welded. Maybe it started to leach stuff into the water. Going take them out.

4. And the last one is going to be controversial. There may not be enough fertilizer in the water. I have a lot of amazon frogbits in each tank and the root has reach the bottom of the tank. That indicates low nitrate. I started doing "more" water change recently to bring down the nitrate in my old tank. By more I mean the regular changes people do (~10% a week). I used to do less than 6 water changes per year and just let the tank run its course (for various reasons). The nitrate used to be around 20ppm and the shrimps didn't seem to mind. I don't have a real scientific explanation for this. The plants are sucking up all the nutrient? The plants are releasing stuff into the water because they are in some nutrient deficient mode? Anyway, I am going to start dosing reduced pps pro into these tanks and monitor nitrate closely.


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## Badlands54 (Dec 31, 2012)

What is the ph gh kh. Are you supplementing calcium in there diet


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## modster (Jun 16, 2007)

pH is 6.6, gH is 5, kH is 0. The diet is sakura shrimp food. 

I think I have tracked down the culprit. My tanks were good for a while after doing the changes I mentioned. Then I lost a couple of shrimps again after start dosing mosura gravidas again.


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## jayr232 (Mar 15, 2014)

Personally I would have my substrate layers a minimum up of 4cm high to 15cm high. I know this might sound crazy but whats wrong with having more surface area for beneficial bacteria? Also, here in Europe, gravidas has been temporarily banned because they have found very little traces of harmful substance to shrimps.


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## niko (Jan 28, 2004)

It maybe useful to read the topic "Organics Analysis" in the "Algae" section. It is a very long thread now but at it contains a discussion about the tap water. Simply put because we live in an age of pollution your tap water can both change unexpectedly and/or continuously bring things that fall under the radar.

If I am not mistaken one guy has tap water that is as clean as his aquarium after a 50% water change. How dirty or clean is his tap water is a question of view - maybe his tank is very clean or maybe the tap water should not contain stuff that belongs to small glass box full of fish.

Bottom line - look at the basics. Usually people overlook exactly that.


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## stanjam (Mar 30, 2014)

I have a few basic rules when it comes to crs. The first is keep it simple as possible. Second is to keep very clean, consistent water (tds 120 to 200, gh 6 or so, kh under 2, ammonia 0, no2 0, no3 less than 10, temp 64 to 76 degrees f). There are some ranges in there, the key is consistent water, and never too large a water change, as drastic changes can kill them. I also use Purigen to remove any traces of metal etc in the water. 
The only things I put in the water are salty bee shrimp, and Prime. RO water is even better than tap, just mix in enough remineralizer to get to 150 ppm tds. My tap runs about 40 ppm, so I have been using it, but enentually will get an ro system just to be safe.

Sent using my Carrier shrimp. U . S . C . S .


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## acitydweller (Feb 14, 2012)

A few things to consider. the toxicity build up in the substrate can eventually leach and water changes would only delay the onset of poisoning. 

Particularly for crystals where the lower ph is actually detrimental to anerobic bacteria development, a thicker layer of substrate would actually do better for them than a shallow one.

Also, i would recommend staying away from seachem equilibrium for any inverts. Ive always gotten mix results and dizzy shrimp using that as a gh booster/remineralizer and have never returned to it. There are far cleaner gh boosters on the market for around the same price.


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## aronson (May 2, 2005)

acitydweller said:


> Also, i would recommend staying away from seachem equilibrium for any inverts. Ive always gotten mix results and dizzy shrimp using that as a gh booster/remineralizer and have never returned to it. There are far cleaner gh boosters on the market for around the same price.


As someone who tops off with distilled water... What remineralizer(s) would you recommend?

A


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