Little Hotties – temperature in the shrimp tank.

I learnt the hard way. Shrimp in nano tanks (around 30 litres or less) get hot – very quickly. I hear many people in the UK say they are not worried about temperature, then wonder why the shrimp died. It is also a key reason why you can not keep shrimp in small tanks without a suitable cooling method (or having them in a very cool, shady house or garage). My shrimp are not in the sun or by a heater – but they used to die from over heating.

Neocaridina like Red Cherry Shrimp and their colourful variations, have optimum (best and healthiest) temperatures for breeding and living. The hotter your shrimp tank, the quicker they will grow and breed – up to a point. That point is around 27-30 degrees C. They then slow down, start to turn white and die.

First attempt – do nothing

I had shrimp survive to about 30 – then sudden mass death. You see we had a heatwave and I was on holiday. I cooked my beloved shrimps. Even some of my tropical fish cooked.

Second attempt – bottled ice water and a room fan

Hot days (or cold winter days with the heating on) once more brought the temperatures up in the tank.

So I then did the only thing I could – put a fan on them and several times a day had a cycle of frozen bottled water going – one bottle floating in the tank, one in the freezer. Constantly rotating and watching the temperature was a real pain . It also meant sudden drops of 5-10 degrees for the shrimp – not good for their health.

The hotter it gets the less oxygen that dissolves into the water – so now I had a problem because the bubbles were on full blast and I couldn’t add any more air to the tank.

Why not an aquarium fan.

Simply the fact that an aquarium fan will only drop the temperature by about 2-4 degrees C. I needed a drop of over 10 at times. The temperature was rising faster than an aquarium fan could cope with. If my mega floor fan couldn’t cope then a tiny fan hooked over the aquarium was not going to cut it – no matter what angle you put it.

Third attempt – do it properly and automatically with a cooler.


I had lost so many beautiful shrimps that I knew the solution was to set up a shrimp only tank and regulate the temperature with a cooler. No more fiddling with bottles and fans.

It was expensive – they are around £300 – but worth every penny.

The water comes out of the external filter, into the cooler, and like a fridge, it assesses how much cooling in needed, and the water is sent back into the tank at the chosen temperature (or within a few cycles if the first pass through is not enough).

So my tank cooler is set on 23 degrees C (when the cooler senses a rise to 24, it cools it back to 23). No worries and it only takes a minute or two to get the temperature down.


We change the tubes to and from the cooler every 4-6 months depending on how much algae is in them. This week, we flushed some tap water through the cooler to give the inside a clean.

You need an external filter to run a cooler and the pressure from that filter pump must be high enough to push the water through the tube circuit and through the cooler. Mine came with detailed instructions.

It was very easy to set up. One thing I would say is don’t clamp the hose on too tight if using tube clips/clamps – I broke the nozzle on my cooler (but still had enough nozzle to reattach the tubes to).

When it’s on, it is a little noisy – but it’s only on for a few minutes at a time and sometimes only for about 3 times a day (hourly in the summer afternoons).


Converting my tank to rain water

With the huge storm last night I’ve been collecting rain water in buckets.

I need to lower the TDS and pH of my shrimp tank as it’s healthier for them. The rain had a pH of 6.2 and TDS of less than 20.

To acclimatise my shrimp I am trying the same technique as introducing new shrimp to tank water – dripping in the water through an enema bag at a rate of about 2-3 drops per second.

Today I took out water then drip added about 1/6th of my tank for its water change. Tomorrow I will do the same again.


My Anubias flowered yesterday.

My favourite plant in my tank is Anubias var. nana bonsai. i.e. A small Anubias.

Without algae it is bright green and started off, looking like this 4 months ago.


It’s classed as a slow grower but mine has taken off like crazy. They don’t need much light and because they are a rhizome plant, you don’t put them under the soil. Mine are held down by a stone and hairnet on too of the substrate. The rhizome is the main stem and it then sends roots into the soil. The rhizome has a growing tip which will push along and from it new leaves will form.


It soon loses it’s bright green when hair algae attached to it – but it’s hard to keep them clean and shrimp like browsing the algae.

This is the flower that shot up in about a week.


I have a hole on one leaf which is a sign of rich organic material around the rhizome ( so a water, filter change or a hoover).

There is also a thought that breaking a leaf at the rhizome releases toxins into an aquarium but many say this is a myth.