Shrimp tale – Episode Five – WATER CHANGE IN THE SHRIMP TANK
#Episode_Five #Shrimp_tale
Topic:WATER CHANGE IN THE SHRIMP TANK
** Before we start the discussion I need to mention this !! What we are going to discuss, is strictly for the shrimp only tank. Fish tank or planted tank with EI dosing has different water change frequency and need. So if you have shrimps in your planted high tech/energy tank follow the weekly 50% changes. **
The water change in the shrimp tank is mainly involved with the shrimp molting factor – something which fishes dont do. Molting of shrimps itself is a large topic which needs detailed discussion but we will briefly see how water changes are related to that.
Shrimps are crustaceans who have an exoskeleton that needs to be changed almost monthly once they are adults. During the growing phase this “molting” takes place more frequently.. almost weekly. So before a shrimp molts its old shell it starts growing a new shell inside the outer one. Before the new shell hardens it absorbs enough water so as to grow large in size and it becomes easier to crack open the old shell when it feels it is ready. This absorption of water happens through a process called osmosis where water flows in from its surrounding through the semipermeable membrane into its body. This is where water TDS becomes crucial. Different shrimps have different parameter necessities however one thing common for them all is CONSISTENCY. A sudden change in the water TDS often results in failed molts or shrimp deaths.
The reason for this is, a sudden change in water parameter leads to MORE or LESS water flowing into the shrimp through osmosis than it would have otherwise. The shrimp doesnt have control over osmosis and hence it may bloat up to its death due to cell damage and rupture. Replacing tank water with a water of higher TDS is the main culprit for this. For eg. My tank TDS is 200 and I replace with water of 230/240 TDS the resulting tds will be higher (based on the avg of the two water type and % of water changed). A shrimp who had planned its molting during this water change will definitely have a hiccup if not die. We see white line behind a shrimp’s neck which is an indication of an upcoming molt or a failed molt mostly. So summing up the best practice for shrimp tank water changes:
1. Have a target TDS range for your shrimp tank. TDS keeps increasing gradually in any tank due to many factors. So when it reaches say 220 you decide to change 30% of water. Bringing back again to 170-180. This depends a lot on the type of water you are using. For RO water you need to find out the amount of remineralising it needs to achieve the target TDS. Tap water users should know their TDS as well to have a range within which shrimps can be kept and water changes are decided consequently.
2. You should never have chlorine, chloramines, copper, ammonia and nitrite in the water you intend to put in the tank. These are fatally toxic to shrimps. Tap water must be collected and stored in open buckets overnight before the water change days. Sodium thiosulphate can be used for removing heavy metals and chlorine from tap water.
3. The temperature of the tank and the new water should be within the same range of +/- 2°C. Exceeding this will have a shock impact for your shrimps. I personally know many people who have lost shrimps right after a water change with a much warmer water than the tank temperature. (So having a thermometer with TDS reading is a general necessity for shrimp keeping.)
4. As we have discussed earlier, for shrimps consistency is more important than getting the exact parameters keep in mind not to make your life difficult with achieving difficult pH levels. If your source water has a higher pH try to keep the species that does well in that parameter. RO water is not an option for everyone but then being careless about tap water is something we should avoid. Know your water parameters well before getting into shrimp keeping.
5. Generally for Shrimp tanks water changes are recommended once every two weeks of around 30% water being replaced with fresh water of lower TDS. This has been found to be least shocking for the shrimps and they feel comfortable in the tank. Shrimps donot have a high bioload hence it is not a problem. However if you have fish in the same tank you need to find your sweet spot.So these are the primary factors we need to keep in mind while changing water. RO water users adittionally need to monitor their kh and gh as well and match them with the shrimp tank parameters. This calibration needs to be done once only because after that you will know the exact amount of salt to be added to a specific volume of water. Recheck once every couple of months.(Please post your comments here if you have any doubt but donot ask for brand suggestions for anything because we donot promote that in this group.)Happy Shrimp Keeping !!