Things I’ve learnt by killing my CRS

I have read almost every CRS guide that I could find on the internet. Some of them are heavily biased towards a particular brand and make things look so easy! Then why do people across the world complain about it being tough? Because it is! Here are a list of things I’ve learnt through my losses, things most of the guides do not say or emphasize.

Test Kits: (GH/KH, TDS, pH)
The single most important kit you need is the GH/KH test kit. Yes, I know GH can be guessed from the TDS, but first of all, when it comes to CRS, guessing does not bring any good, second of all, read first of all. CRS has a wide range of acceptibility for TDS (90-150, even 200) than it has for GH (4-6). Keeping a TDS of 120 does not ensure your water has the perfect GH for shrimps to molt properly. You should mineralize your RO water to have a GH between 4-6 not for a certain TDS. Then whatever the TDS the mixture reaches, thats the TDS you should aim for always. KH also plays an important role in keeping the water parameters stable, specially the pH. Internet says its okay to have KH 0 but in fact its not. Having a KH 0 means your water is prone to sudden pH swings. Having a KH value of 1-2 is equally important. You should also aim for a pH below 7.0 but this is not the end of the world, slightly above 7.0 is okay too as long as it always remains that way.

RO Water pH:
It is advisable to use RO water for CRS. Dont get fooled by the pH measurement of the bottled RO water. It will read way below 7 but if you keep it in an open place for an hour or two or preferably overnight, it will climb towards 7 or even above 7. Do not ever measure the pH of the water unless its been aged for a couple of hours to 24 hours depending on the water volume.

You should always aim for a soil that buffers the pH of the tank to less than 7. But if your water has a very high KH, the substrate can not help you. Amazonia II buffers the soil around pH 6.5, Africana to pH 6.0 and Malaya to Ph 5.5 approximately. Please note tha you must have a fat (at least 4cm) layer of substrate for the soil to be able to buffer properly.

Temperature:Do not even think of keeping CRS in temperatures above 26C. You will not have much success. The ideal temperature is between 21C and 23C but keeping a stable temperature without fluctuations is much more important than struggling to keep it low. That means, if you can manage to keep the temperature stable at 25C, that is the better option than trying to force it to 22C but fluctuating it between 21C and 26C.

Water Change:
When it comes to CRS, what do we say to frequent water changes? Not anymore! Frequent water changes cause more stress and does more harm than good. If there is one single thing CRS dont like, its “CHANGE”. If your Ammonia, Nitrite and Nitrate reads within the safe zone, dont change water. If you have a good filtration, you could go upto 6-8 weeks without water changes.

Also make sure your water is aged at least a week before releasing CRS into the tank. This means, do a 80-90% water change on week prior to introducing CRS. Check for water parameters one day before and make sure they are stable. This means, your tank water should read:

Ammonia/Nitrite: 0
Nitrate: 0-5
pH: 6.0 to 7.4
GH: 4-6
KH: 1-2
TDS 90 – 150

No planted tank:
It is impossible to balance the need of a proper planted tank and CRS at the same time. Pick one. Yes, your tank better have some plants for CRS, but those should be low demanding plants i.e moss, ferns etc, not resource hungry red plants or hairgrass. CO2 is also a big NO, in fact CRS prefer a O2 rich water.

I would avoid having any kind of stones at all, other than may be those mineral stones sold specifically for shrimps. Rocks and stones may cause the GH instability in the tank and also cause pH swings overnight. However, driftwoods are okay, in fact preferable. Its better to set a dedicated tank up for CRS using a fat layer of substrate, easy low tech plants like moss and ferns tied on branch wood and optionally mineral stones. No fancy rocks, no fancy plants!

Again, CRS do not like changes. Do not put your hand inside the tank, like ever. Use a long twizzers to do stuffs you’d use your hands for.

And now, some pictures of my CRS, which I’ve lost in the process of learning.

Crystal Red Shrimp

SS/K10 Crystal Red Shrimp

Golden Bee Shrimp

Golden Bee Shrimp


31 thoughts on “Things I’ve learnt by killing my CRS

  1. Hey, you said that RO water can read way below 7. I’m having the problem right now, I’ve gotten RO water from a few places and it gives me a pH of 5.5. I’ve tried to keep it in an open place for a while but that did not work. Do you have any ideas why it’s not working?

    • Try measuring it after keeping it in an open place for a whole night. If it still reads 5.5, then, well you’re lucky! 😉 The main thing is to keep the parameters stable. Doesn’t matter if its pH 5.5 or 6.5, whatever you decide to maintain, should be stable.

  2. Hi Fahad,

    I came to google and found your guide on crs. it is a very good guide. thank you. may I get advice from u that when doing water top up, can I use mineral water or distilled water?

    thank you

    • You should always use RO/distilled water for topping off. Its because when the water evaporates, the minerals stay behind. If you add mineral water this will lead to an increase in overall hardness of the water.

    • Hi Fahad – does this mean you are topping off your CRS tanks with RO water that has a 0 TDS reading?

      Thank you,

  3. Hi… First, thank you for this thread, it’s very helpful. But I am still a newbie. I read this thread but I don’t understand some parts. Could you help explain?

    1.GH and KH, mine read to 8GH and 8KH.
    Although the measurement are (8 dKH) & (8 dGH). And while you said GH 4 to 6 and KH 2. Are those measure using dKH and dGH? I am using sera test kit. According to instruction. 8 drop for each which makes it 8 for both KH and GH. How to lower them correctly and effectively? My water is auto filled. It ran through R/O system. Although I’m not sure how effectively my system are, it’s not that expensive, and it’s the only single Brand in here.

    2.Is daily water change really a bad idea? I was told to do a small water change daily is better than Large water change every week. I changed 20 to 25L of water everyday. My planted tank is about 400 in total.

    3.While I do see some Fire Red Shrimp Babies, I never saw any CRS. And now recently my Yamato shrimp started to swim like it was poisoned and would die almost 1 for every 2 to 3 days. My Temp is at 24 to 26C, my Chiller stopped at 24 but would only continue working when the water reached 26C which will took about 2 to 3 hours to get it down to 24C. I am assume some CRS are dying too but I never saw them dead but I did often see Fire Red dead and when Fire Red dead, it looked somewhat purple or blue color. And the dead ones are usually a big ones.

    4.I never feed my shrimp. I used expensive food from Japan but none of them eating it. It would search for it at first. But after a couple hours, the food would scatter everywhere on the sand. So I don’t feed them. But now I order Spinach Food, because I am trying to color up my CRS and I’m trying to keep only CRS, Yellow Shrimp, Fire Red Shrimp and Yamato Shrimp & Bamboo Shrimp, I checked compatible chart and they are compatible to keep with one another without Cross Breeding. The only fished I keep are Panda Loaches, it safe to keep with Shrimps. These Panda Loaches are only recently been introduce to aquarium, it found in a river in China nearly the mountain where they also found Giant Panda too. Exotic, right?

    5.I check NO2, it’s at 0.5mg/l. Is that alright? some measurement is using ppm. But I don’t know how to concert mg/l to ppm. Sera Test Kit read Mg/L.

    6.My pH is at 7.0 to 7.2. I used CO2 along with Drop Checker. I am trying to keep Drop Check at Green Point. Although I do use pH Pen for measuring from time to time. And it read to be 7.0 to 7.2. Should I lower it more? My lighting is auto off. I am trying change to Solenoid Regulator too, so I can have CO2 turned off while my Light is off too. Is that a good idea? I already order Solenoid Regulator, only now waiting arrival. Since my CO2 is at full speed when lighting is off, which mean the Plants are no longer consume CO2 at night. I am thinking an unstable pH is reason my shrimp are dying.

    7.Anything else to recommend me?
    And idea and instructions would be appreciated, thank you very much for your time.

    • 1. dGH and dKH: Dose half of what you’re dosing right now. Can you measure the TDS? It shouldn’t be more than 150-200. DO NOT make any sudden change, any change you make, so it over a span of a week.

      2. Yes. 400L is a good volume and you should only change water when the Ammonia and Nitrate levels are high. Its better to do frequent smaller water changes than one big one.

      3. I think the temperature fluctuation is the culprit here. Try to keep it stable.

      4. In a planted tank shrimps almost never needs feeding. However, they do need different diet once in a while. Try BorneoWild foods, they are good.

      5. Should be okay.

      6. For CRS, pH should be kept below 6 and stable. Using ADA Malaya soil will definitely help buffer the pH to around 5.6-6.0.

      7. You should not try and mix different types of shrimps. Get a separate smaller tank for CRS where you can monitor them, feed them and tweak the parameters to their liking.

      All the best 🙂

    • Ideal Water Parameters for CRS
      PH 5.8-6.2, KH 0-1, GH 4-6 TDS 140-160, Temp 22-24

      your PH is too high for CRS they are very sensitive and fluctuating water parameters can cause stress and eventually leads to death.

      CO2 is not good with CRS, Usually CRS kept with low demanding plants like different kinds of moss,bucep and ferns, these plants are low demanding, and dont need co2
      Drift woods can help lower PH, If possible try to place some Alder cones and some Indian almond leaves,Boil them first for 10 minits then let it cool and just place it in aquarium, Youtube has lot of videos on them,

      CRS can be kept with cherry but fire red and yellow cant be kept in one tank,they both are same species and will interbreed resulting in cull offsprings, rest or the shrimps in your tank are ok.

  4. Thank you for the Replay. Much appreciate it.

    1. I can’t do TDS, don’t have any test kit for it. I will get it. But is there anything else I could do in the meantime?

    2.I will keep up with small water change.

    3.There is no way to keep it stable. Unless, I forced my chiller to run 24/7. Even if I change Chiller to a bigger one, it would still Auto On/Off. My house is 28c for normal. Once the temp reached the set point, the Chiller will stand by to save power, it would only work again when the Temp is increasing. Although bigger chiller might need less time to cool the water down which would have make it more stable. But the problem is electricity in here are too expensive, and I have no space for bigger chiller, my chiller are just right for the size and the Litres. And the bigger one than mine is $750 in here, it’s Hailea HC-1000A.

    4.Wow,… what a coincidence, I just recently contact BorneoWild branch in Vietnam about a few days ago after I found BorneoWild Colors in eBay. They have more than one kind of food. I thought of buying all of them and feeding them using different days and weeks to feed different kind of foods, so they would get to eat all kind of different food in each week.

    5. I’m using Ceramic Rings and Other Carbonate stuff to help remove Ammonia and Nitrate. And I just added Azoo Water Pillow today, To help lowering hardiness of water, it require to replacing every 2 months.

    6. There is no way to lower pH down unless I used more CO2 by using a pH Controller. Changing Soil is out of option, My tank is 120cm. Fully set up. And replacing the soil would cost a lot because I would need place to placed my shrimp and fish, I would need to take out a whole decoration and of course, doing that, would destroy most plants. Most of my plants are very expensive, they don’t have it in here, I order some of them from overseas. And I would need a stabilized tank to move everything, and it would take at least a week to get everything done. When I first saw “Artificial Soil” on the bag, I didn’t put much though into it, I thought of it was just to replace real soil, mostly was to help with the weight, because I though it weight twice less than real soil if we compare the size…, every other description was in Chinese, I didn’t get to read about using it to stabilizing pH or otherwise I have ordered a better brand name. So I used Taiwanese cheap soil add along with white sand, Because this artificial soil is not sticky or firmly hold together and any plants could easy lose around or any fishes can easily pulled it off the ground, so I add white dead sea Sand to make it more firm and stronger so I can plant Aquatic Plants better. Indeed, they hold plants better than full artificial soil but I’m not sure about the stabilizing pH part. Is mixing them with Sand, a bad idea? I have my gravel set up like mountain from low to high, so my soil is 10cm at front which reach up to 30cm at the back of the tank. They only recently importing ADA Soils, it’s cheap too and as much I love the brand name and wanting to change, that is out of option unless I have another $500 to burn. A new back up tank would cost almost $200. And new pumps, new plants, probably some more Panda and some shrimps would dies and I would need to buy more. It’s $4.5 for a CRS. It’s going to be $500 and up for sure. Anything else you could suggest? Getting a pH Controller won’t be a problem, if that could solving the pH stabilizing part.

    7. I know that as well that’s why I google around and found compatible chart… But the idea is to have an exotic tank with exotic shrimps all in one. I am decorate my tank to look like deep exotic forest. Oh man, I wish I have FB or Line or Viber, I could send you picture of my tank. The imagination was, while my decorating is attracting, when people take a closer look at the decoration, trying to read the details, they could see those beautiful tiny creatures crawling up and downs, the trees. I could build a smaller tank for CRS, but for who to see? I am not selling them or anything, this is for my house decorations, If the landscaping of the tank is not good point, I might as well just throw those shrimp in a bowl somewhere and let them breed and live there. Wouldn’t you agree?

    I could raise Neon or Guppy, I think Guppies are better because I love long-fin fishes and since they don’t school, it’s better that way, I tried them one, they each seems to be doing different thing, at different places, it was very good, scattered every corners of the tank and doing their own things, it was so beautiful. But they’re not exotic creatures, they are the most common ones of all aquarium fishes and I really hate it when my tank is filled with Babies. It looked like a cheap/crowed place. I love just having 5 or 6 fishes, swimming around, scatter everywhere. I tried to keep all males but without females, the males would chase each other, even causing worn and dies. Some of them have their scales torn off.

    While neon colors are striking beautiful, they’re not that attractive, because they schooled and they move to the same place and doing the same thing, it’s like they in military school or something. And I hate that as well. I love Cory Catfish though, they’re individual, it’s nice to see them trying to find food without caring for the world, they look so free and so uncaring about anything else. And I love that part in any fishes or any pets.

    Hopefully, I can make my Landscape Planted Tank successful enough to keep CRS.
    Thank you for replying back and thank you for time.
    And if you have anything else to suggest, please do so.
    I am very appreciate your help.

  5. Hiya I too have just started to set up a tank for shrimps like you I have watched all the u tube vids prob red through half the Internet and strange how no one seems to agree on temps ect….. However reading your information was very interesting and made a lot of sense such as water changes to often my moto as always been if it’s not broken don’t try to mend it even with some tropical fish I have kept lots of time evaporation gone once replaced is enough…. I would like to ask some plants come with lead weights is it advisable to remove this weight I wouldn’t need it as I have substrate and fine gravel so enough to plant it?

    • Yes, you must remove it before putting it in tank. Also its important to quarantine any plants before introducing to an established tank because a lot of these plants are treated with copper solution to treat unwanted pests and snails before shipping. Just put them in a tank/container with good flow for 12 hours or put them under running water for two hours.

      Best of luck with your project 🙂

  6. Thanks for your reply yes I had been leaving the plants in water lots of sellers of plants will advise of this so I tend to do it with them all and I did remove the lead weight I don’t want nothing in the tank which could pollute it, it’s all going fine at the moment fingers crossed but I’ll continue with water changes and keep checking before adding any shrimp.
    Thank you for your advise it’s much appreciated.

  7. Hi thank you for article it was really useful but i was just wondering if i could get some information on setting up a crs tank. I haven’t setup my tank yet but I’ve already got some things. I have a TDS meter and my tank water has a TDS of about 60 and i also have Mosura Bioplus, Mosura Tonic pro, Mosura excel, Mosura Old sea mud powder, Mosura BT-9, 2 sponge filters, ADA aqua soil amazonia (powder type) and Hikari shrimp cuisine. But I’m not sure how to set up my tank properly and I’m planing on using the Mosura feeding matrix but i will replace crs specialty food with the shrimp cuisine. I have a 2 foot tank and I’ve also got lots of java moss and drift wood that i plan on putting in the tank. I cant really afford a RO unit and but i think my tank water should be alright but i think i will need to get something to increase the TDS or will some of the products I’ve got increase the TDS. Also what should go under the grave, like i have a bit of a idea but I’m not certain. I’m planing on breeding crs and I’m going to start off with 10 A grades. I’m just wondering what else you think i would need, any information will be very appreciated, Thank you

    • Yeah sure why not. As long as you give credit and link back to the original article, feel free mate 🙂 Post a link here as well so that I can see.

  8. hi Fahad,

    here’s my plan – Making a rectangular tank – W 2ft , length.2ft height 12 inches or 18 inchs.
    Questions – Can I use Contra soil or use without the substrate ? what is best .
    Is it okay to keep the Tank empty just add some drift wood and moss may be .
    Im currently using JBL algae wafers
    The water/temperature I understood the concept no problem with that . Need your suggestion

  9. Hey

    I have a 30W LED FloodLight that i have going to put on a 30cm deep tank. the tank its self is 40 litres (10 gallon). is that too much light?

  10. Salaam,
    may I know, do You continue keeping and breeding crs variant ?
    I learn much from Your article above. Salaam

  11. Hi Fahad I found this via search for TDS and High dh…i am just starting out, and have, like julieb – read everything i can find and there is so much conflicting info.
    I am writing short sentence first…to see if you are still there.

  12. I learned a bit reading your blog..i hope you are s till there. Have Ghost, black and blue and reli orange tiger….anyway…my tap water comes out 7.4/7.6 and kh 1 dh 3. tds @ 60.
    Using, currently Salty Shrimp Mineral Gh/Kh+ and my values increase…
    Fluval Spec 2.6 with Cu absorber;
    Just added everybody yesterday and moved an overgrown angel to another tank, so this tnk has been up and running for over a year now. Is one of my most stable.
    I drip acclimated using an IV Pole (Im a ((lazy)) nurse( and gallon jug/tubing.
    Last night Values PRIOR to adding anybody:
    NH3 Trace
    PH 6.6
    Temp 76.5
    NitrAtes: 40
    Nitrites 0
    Kh 6
    Gh 4
    TDS 380

    NH3 0.5
    Ph 7.4
    NitrAtes 30/40
    Nitrites 0
    Kh 7
    Gh 11
    TDS 487

    Did a 1/2 gallon water change – drip method and dosed with half dose of salty shrimp/ 1/2 RO water and 1/2 mature water from tap treated with prime.
    WHY are the kh/gh/tds elevated and i am guessing this is way out of whack for shrimp?

    in advance

  13. Hello Fadah,

    I wish I had found your blog under better circumstances. Right this moment my kid’s CRS is struggling at the bottom of the tank. He’s been here for about 10 days and until today he was always very active and fine. Today I did a 15% water change… maybe that did not agree with him, although it was not the 1st water change since he’s been here. I know you’re not a vet, but form your experience, if a shrimp is sideways at the bottom of the tank, is there any chance of recovery? Is there anything I can do. He does still try to move and he does still occasionally swim around, but bumps into things. Of course, my kid is sad and if there’s anything I can do, if there’s any hope at all, I want to try. Although I have a feeling it’s too late.

    My pH is 5, ammonia, nitrite and nitrates are all 0, GH is 5. It’s a 10 gallon cycled tank with 4 cory cats, 1 CRS, 1 dwarf cray fish and one snail. Sand substrate, grass, swords and floating plants. A lava rock bio filter.


  14. hi fahad since you rote the articale on crs as any of your information changed as reguards to water changes as i still do 20% weekly my black bee are thriving yet my crystals have dropped off and i think this was due to the mistake of doing water changes to equil tds as a result my gh went up and they stopped breeding
    cheers richie

  15. Sorry guys I no longer keep shrimps nor do I maintain this blog anymore. I appreciate you guys reading the post but I wont be replying to your questions as the things I know may not be valid anymore since I have been out of the game for too long. Best wishes!

  16. Hi Fahad , i need your help. In my 1o gallon crystal red tank i used to use fluval shrimp stratum with RO water and bee shrimp mineral to get tds 120. My Ph would be around 6.2. My stratum got old and was time to change so i decided to not use active substrate because cleaning and changing it was a nightmare. I went ahead and redid my tank a 2 months ago with regular shrimp substrate that i use for my neos by aqueon that doesnt buffer at all. Im still using RO water with bee shrimp mineral to get tds of 120. The problem starts when i went to check my ph in the tank. My ph is 5.2. The ph meter is fully calibrated so i know it is accurate. I had a lot of almond leaves and cones in the tank so i removed it but that didnt really make a difference. My question is , is 5.2 ph too low for cystral reds? My objective is to get them to breed. I dont understand why my ph is lower now vs what it was with the buffering substrate i was using which was meant to lower my ph. Should i leave it be or raise my ph to 6.2. Right now bee mineral doesnt have kh so i was thinking if i mix salty shrimp gh kh with bee shrimp mineral Gh , 60 tds each, it will give me a kh of 1, gh of 5 , and tds of 120 before i put the water in the tank and the kh shoul help to stabilize my ph around 6 . What do you think? What should i do , leave it alone or add some kh? Why is my ph lower now then i was with active substrate when i didnt change any thing else i was doing. Please help!

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