Opaeula.co.uk

THE forum and online store dedicated to Halocaridina rubra aka the Hawaiian Opae ula shrimp! 

How to care for Opae ula shrimp

Page Index:
Feeding
Water changes
Tank maintenance
Light source
Temperature


Feeding

Feeding routine is key when it comes to this species of shrimp. With normal ornamental fresh water shrimp like cherry shrimp you tend to feed them every day to every other day, this is fine because you change a % of their tank water once a week. The nitrogen cycle turns the waste and uneaten food into ammonia which becomes nitrites then nitrates. Nitrates are not as toxic as ammonia and nitrites so when the levels of nitrate creep up over a week, keepers change out water to lower the measure/dilute the nitrates then the new week starts over. However with Opae ula keeping you don't do water changes, it upsets them and the stress will prevent them from breeding etc. If you wish to eliminate the water changes you need to prevent a build up of nitrates, therefore remove ammonia and nitrites out of the equation. This means ONLY small feeding quantities once every 2 weeks for a small population of shrimp, and once a week for large quantities of shrimp.

The shrimp will eat biofilm and algae that grows naturally in your tank so they won't starve but it's good to give them a little extra to provide nutrients which promote breeding and good health. The very little waste from the tank inhabitants which is produced will be enough to be turned into a food source for the algae but not enough to build up and foul your tank water.


Water changes & quality

As you have probably read the less water changes the better as it disturbs the shrimp less but sometimes you may have to provide a water change depending on the waters parameters or in emergency situations e.g. Contamination or poisoning. You shouldn't change more then 50% of the tank water in one go as this swings the tanks stable environment out too quickly and could shock or heavily stress out the shrimp. I'd advise a 25% water change and wait a day or two then provide another 25% if needed. You can remove water with a container/jug by hand or use an aquarium substrate Gravel cleaner and remove some of the shrimps waste from the surface of your sand at the same time as it removes water into a bucket.
Here is an Aquarium gravel cleaner:



It's always handy owning one of these because it has two handy uses, 1. It can be used to remove water from your tank into a bucket if you wish to do a water change and 2. If you have any uneaten shrimp food in the tank after feeding time which is out of reach or deep in the substrate you must remove it somehow and that's where the hoover helps out! With the gravel cleaner you can hold the Hoover over the area of the food and suck out the remains without removing too much water and preventing food spreading around down too much which will eventually break down and produce ammonia -> nitrites -> nitrates = unhealthy water and water changes needed. I use a glass feeding bowl to feed which makes removal of uneaten food a breeze.

Also using the gravel cleaner inline with a feeding bowl prevents large water disturbances, restricts the amount of water removed by the gravel hoover and stops it also picking up any substrate thus reducing stress to the shrimp.
* It's important to try and match the fresh salt waters SG/salinity to your tanks levels before adding the new brackish water mix. Never add Salt directly into the tank if you have any living shrimps or snails etc! Always mix separately in a bucket, take a reading with your refractometer/hydro meter and once satisfied slowly/carefully pour the clean water into the tank and to try and avoid stirring up the substrate to much. Your main aim is to get the freshwater in without stressing out your shrimps!





Tank maintenance.

Initial start up daily maintenance:

Quick inspection in the tank for signs of anything wrong. If you have shrimps in the tank from the start look for signs of:
      • Pale shrimps (stress or poor water quality)
      • Constant frantic swimming (stress or poor water conditions)
      • Dead shrimp or snails (poor/wrong water conditions)
      • All shrimp hiding (poor water conditions)

Next a quick inspection of the thermometer to make sure the water temperature in your tank is correct, this will also show if a fault occurs with the heater (stops working all together or gets stuck to the ON position and overheats the water).
Also check the water parameters with a liquid test kit for:
      • Ammonia
      • Nitrites
      • Nitrates
      • PH

*NOTE* If water changes are being made to reduce ammonia or nitrites with shrimp already living in the tank then matching the waters salt content prior to adding and checking the tanks over all SG/salinity afterwards is always good practice. If using a Hydrometer wait for the water to come back up to temperature in the tank before taking a reading. The temperature difference of the new cold brackish water can give a slight inaccurate reading.


Every other day:

Water top offs using only pure RO water to replace evaporated water loss in the tank. I find it a good idea to get the water to the desired level and SG/salinity then add a marker on the outside of the tank so you can see when the waterline drops from evaporation and you know where to fill up to with pure RO water.


Yearly:

When testing monthly for nitrate levels, if you start to get readings above 10ppm which may take 6 months or longer (in some cases never reaches this) then a partial water change with some fresh brackish water is advised (around 20% of the tank). If the nitrate levels always rise quickly then something has either died and is being broken down or you are over feeding the tank with food.


Conclusion

The above is just a rough guide and doesn't need to be followed to the T, but being cautious and keeping on top of the water quality will help keep your new shrimps healthy, happy and encourage breeding. 99% of the time when you run into issues or problems you will always end up doing a partial water change to remedy the situation, testing your water parameters consistently with a test kit will always point you in the right direction or show why the water is becoming fouled/what caused it thus knowing what to correct. Once your tank is fully established and you have a good feeding routine you will find the less you mess around with the tank and change things the happier the Opae ula shrimp will be, sometimes less is more!


Light source

I'm going to split this topic into 2 sub headings, natural light and artificial light.

Natural light:

While this is a cost effective and natural resource to use it can be a bit of a double edged sword, the issue with this setup means you must get indirect sunlight to your tank to grow algae which is the shrimps food source. If you get direct sunlight it can alter and raise your tanks temperature, within the UK outside of the summer season you don't have to worry about this as it's usually too dull and cool to affect the waters temperature. The summers don't usually get warm enough to equate to water overheating but I wanted to mention this. How ever if you live in a country that does get really warm and you get direct sunlight on the tanks glass then you need to be very cautious and keep checking your thermometer.


Artificial light:

This is the easiest setup to use as you can buy a plug socket timer which will flick your light on and off depending on the hours you set it to operate. My timer comes on at 7am and switches off at 7pm. I use 2x 50watt lights in my main tank and a single 10 watt LED lights for the smaller cubes. 12 hours on and 12 hours off is really all that is needed to encourage algae to grow. If you have slightly underpowered lights then it's wise to let the tank get some indirect sunlight or direct for a very very short time so long as it doesn't raise your tanks temperature too much.

It will take a few months for algae to start growing in a new setup so don't panic at the start if you don't see any growing strait away. Just as a reminder these shrimp can go long periods without food.


Temperature

The Opae ula shrimp can survive in waters ranging from 15 degrees C up to high 20's but are most happy around the 20 - 23 degree C mark. Depending on your country and house temperature you may need to provide a heater or a chiller. I cannot comment on chillers to reduce the temperature because it will never be needed here in the UK but the option is always there if needed, in extreme cases if you do need to lower the tanks temperature you can put cold water and ice in a sealed plastic bottle and put into the tank to cool the water slightly.

Coming back to the option of a heater I would highly advise one in your tank if you are located within the United Kingdom, shrimps in general always require a stable environment and water parameters so if the tanks temperature swings up and down a lot or aggressively it will upset/stress your shrimp. Opae ula will 'survive' this fluctuating environment but won't breed and show their nice deep vibrant colours.

When you buy a heater you first need to find out how many litres of water your tank holds and match up the heater in watts. E.g. My tank is 67 litres so I will need a heater of a minimum of 67watts, you don't want the heater to struggle so always get one slightly higher rated, I went with 100watts and this works perfectly. If your heater struggles to get the tank water up to the desired temperature it will wear out quicker and may break prematurely. The heater operates by having a thermostat built into it, when the thermostat detects the tank water drops below the set temperature it kicks the heater into action and starts to warm up the water. As soon as the thermostat reads the water coming up to the set temperature on the heater it switches off. This keeps your tanks temperature regulated and stable.

Issues and precautions for heaters:
• Under powered may break down from excessive use.
• Stuck switched to 'ON' because of a faulty thermostat causing the tank water to overheat.
• Breaking if switched on out of water (watch out for this during water changes as the water level drops)


Water parameters

In this section I will talk about water parameters.

Nitrogen cycle
You can read about the nitrogen cycle HERE in depth, if you understand the cycle already you can see what water quality keeps a healthy tank stable. In short you want these water readings;

Ammonia - 0ppm
Nitrite - 0ppm
Nitrate - as low as possible, over 10 - 20ppm and you are asking for trouble, if so a partial water change is needed.
PH - 8.0 - 8.4

The PH is the level of acidity in your tank water, the Opae ula shrimp favours a high PH for healthy molting, living and breeding. I would not advise using a chemical or liquid product to raise your tanks PH, if it sits low on the PH scale or starts to become higher in acidity (8.0 and below) then it's a sure sign your water is or is becoming too acidic. You can buffer your PH by using crushed coral for substrate instead of sand, ocean rock as the tanks scape instead of lava rock, introduce a small food bowl with crushed coral in it or buy a block of calcium Carbonate (fish tank safe and rated) and pop it into the tank. As the water starts to become acidic over time it will start to break down the above ever so slightly and what's released will raise the PH back up to a healthy level for the Opae ula.

If your PH drops very low you risk the chance of a 'tank crash', this is where all of your beneficial bacteria you have grown in your tank to take shrimp waste and uneaten food etc dies and the tank can no longer keep the water healthy and ammonia free until the cycle gets restarted and stable again which can take months. During this time the ammonia will be present and kill all life in your tank. The issue of high acidity (low PH) is it can stall your tanks cycle when your tank is being started from new or recovering from a PH crash.