CRS help

[tsze001]

Hi all, I'm new to shrimp keeping and is having problem keeping crs alive, at the moment the tank has a slight hazy white/green water and several crs has died.

Tank: 38cm(W)*23cm(D)*27cm(H) roughly 20Litres
Substrate: ADS amazonia power.
Plant: HC Cuba carpeted whole tank, growing well and some are pearling.
CO2: pressurised CO2 at 6 bubbles per minute, shuts off when lights off.
Filtration: AC50 Hang on back with Sponge intake, ceramic ring, PolyFilter, and filter floss
Water change: 10% a week
Temperature: 22degC to 23degC
Lighting: 4x 3Watt 10000K LED, 8 hours per day.
Water Parameter: 0ppm Ammonia; 0ppm Nitrite; 20-30ppm Nitrate; 6-6.5pH; 1KH; 5GH
Added supplements: Half a Almond Leave; 2 Shirakura Mineral Rock; I use RO water and remineralised with Salty Shrimp GH+; also sprinkle some GenChem Beta-G immune booster.
Inhabitants: 2 Chilli Rasboras; 8 Crystal Red Shrimps --> 5 died one by one

The tank has been running with only plants for 2 months, I'm pretty sure its fully cycled since ammonia and nitrite are both zero. Added fish and shrimp, then water starts to get a little hazy white, I thought its a bacteria bloom but the filter floss is light green. Recently, even the water has definitely turned a hazy light green colour, so I believe it is algae bloom instead, I did a 30% water change and now its back to a hazy white. All the time I've checked the water parameters and ammonia and nitrite are always zero. Nitrate is always about 20 to 30ppm, I can't lower it even with 30% water change. At the moment I'm waiting for some Water Lettuce to arrive to try and combat the Nitrate and the green water.

I don't know what is killing my shrimps, I do see some whole molted shells but I don't know if all of them molted good. I don't believe green/white hazy water condition will kill them? Any ideas to help save my remaining shrimps are welcome.

Thank you.

 

[Lindy]

As this is high tech I would assume you are dosing ferts? What is the gh and tds of the tank as these are major factors in keeping crs happy. It seems like a lot of light for such a small tank but then you are using alot of co2 as well. Co2 and crs doesn't alway mix well. Shrimp also need acclimatised slowly, preferably by drip method. Have you lost any fish or did you start with just 2 fish? If there have been jumpers your co2 may be too high.

 

[tsze001]

Hi Lindy,
I do have Flourish Excel, but I heard they are bad for CRS so I stopped dosing when I introduced the shrimps. The GH is 5 and TDS is 166ppm. I haven't lost any fish and they don't jump. What is the normal CO2 bubble rate?

 

[Dane]

Your nitrates are excessive for CRS. Anything reading over 10ppm and the shrimp will struggle to build a new 'shell' after moulting.

Is there a certain time they are dying? During/after moulting, in the evening?

 

[tsze001]

Hi Dane, I believe it's after molting. The dead shrimp usually have part of the shell lifted up near the head area.

I will try and lower the nitrate, I've putted some water lettuce in yesterday. Hopefully it'll clear things up soon. Thanks.