The warm weather and long days are ideal for ponds, but they offer potential benefits for indoor fish, too. Make the most of the rest of the summer with these simple ideas.
is a former PFK editor and now Evolution Aqua’s business development manager. He brings us some great outdoor projects to benefit you and your fish.
1 Make RO water
With no risk of frost, you can fit an RO unit to your outside garden tap. There you can merrily fill 25 l drums galore, without the anxiety of what to do if it overflows. Run it 24/7 (if you’re not on a water meter that is) and if your drums fill and spill over into the garden, no problem. And you can water your garden with the gallons and gallons of waste water produced.
2 Culture live foods
There is no better thing in the world than free live food for freshwater fish, and in the summer live foods are available in abundance, in your own back yard. Fill anything with water — and I mean anything: a bucket, a dish, a polythene sheet — and within days all those annoying gnats and mosquitoes will find it and lay their eggs in it. I get two forms of larvae; bloodworms which form little detritus nests on the bottom and black mosquito larvae which hang at the surface. Throw a few brown tree leaves in and you’ll have a constant supply of these two fish foods throughout the summer.
Using a standard sized fish catching net I can harvest a decent feed once a week, even from only a few litres of water, so by placing water all over the place you’ll get daily feeding quantities. Just keep fish out, as obviously they will predate the larvae. Look closely on the surface and you’ll see black floating rafts of mosquito eggs. I skim these off with a jug and feed those too. Small tropical fish were literally made to eat live gnat and mosquito larvae!
If you want to really push the boat out, farm Daphnia too. For a pound or less I buy a bag of live Daphnia from the fish shop. Don’t worry if they are looking ropey in the bag — you’ll only need a few live ones to start a culture. Again, these need only a few litres of tapwater, but this time I leave it out in the garden until it goes green. As soon as it does, the Daphnia can go in and you will have swarms of very healthy live food within days to weeks. Plan ahead so you always have a bucket of green water ready and you can simply net some out and place them into the next bucket.
If you only have only one vessel, no problem, — you can feed Daphnia on the tannins from oak leaves, algae and even detritus from when you clean the filter media. Several times I’ve actually acquired Daphnia for free. At my last house, some polythene sheet was put on the ground, it filled with a few inches of rainwater and some fallen oak leaves and to my surprise, the most robust, colourful and abundant Daphnia I’ve ever seen turned up in it. I don’t know to this day how they got there!
3 Breed your pond fish
If you want a low hassle, fun fish breeding project then why not breed some of your pond fish? Choose a plump female and at least two males and place them in a shallow tank or vat with gentle, air powered filtration. Place them somewhere the vat will catch the morning sun and wait until water temperatures hit 20°C. Add some feathery oxygenating plants, wool spawning mops or Koi spawning brushes and they’ll spawn like clockwork.
You can raise the subsequent fry quickly on newly hatched Artemia (brine shrimp), but if you want nature to take its course, remove the adults, slow the filtration down even more, let the water go green, add live Daphnia and you are away.
There’s something wonderful about the food chain that is water-algae-daphnia-fish. If you have enough of the first three, the fish will survive and grow all by themselves. It’s a very low maintenance breeding project, uses hardly any electricity or bought food and it’s a lot of fun.
4 Breed amphibians
The nation’s amphibians need you, so if you haven’t got any form of water in the garden, please consider some. It doesn’t even need to be an actual pond, or very big. This year I laid down an old fibreglass tray on my decking. It’s only 10cm/4in high and it filled with 7.5cm/3in of rainwater. Despite no previous pond or signs of frogs, they found it, spawned in it and I raised several hundred tadpoles to frog stage, where they hopped off and can now occasionally be seen in my flower beds. When the eggs hatched, I put plenty of oxygenating plants in, and when they became free swimming tadpoles, I fed them on dry fish foods. Provide a home for them and they will come.
5 Farm algae
Summer time doesn’t have to be all about fighting green water and blanketweed. Algae can also be your friend. Greenwater is good for conditioning Goldfish and Koi, and for feeding to Daphnia, but other types of algae can benefit your indoor aquariums too. Place rocks and wood in water outside and wait for them to go green. That lush green matting on the surface is perfect for all kinds of algae grazing indoor fish to feed on, from mbuna to plecos to livebearers and even freshwater shrimp. And it costs nothing. Circulate rocks and wood between outside and inside so you always have some algae covered ones to move in, and some grazed ones to replace them and go back outside.
6 Soak bogwood
Keeping wood underwater also has the benefit of pre-soaking it. Far too many aquarium woods sold these days actually float, and there’s nothing worse than spending days aquascaping an aquarium only for everything to flip upside down and float off when you fill it. Water butts with lids are good for soaking multiple pieces of bogwood, or even just throw the wood into your pond to be retrieved at a later date.
7 Seek inspiration
You may have been lucky to have visited rivers and streams in tropical countries, but the good news is that the UK’S are exactly the same, only colder. Go for a walk and study the local streams and rivers. Watch the flow and how the water moves and, if you’re lucky, the way the fish swim in it. Look at the substrates and boulders and how they intermix and where. Study the undercut riverbanks and the overhanging foliage and where any true aquatic plants are growing. A typical UK minnow habitat perfectly replicates danio habitats in Asia, so reproduce that for Asian riverine barbs, danios, rasbora and loaches Look at the dappled lighting and light/ shade contrast throughout the day and replicate this with controlled LED spotlighting over one end of the tank. Look at where the fish hang out — small fish seek the safety of shallow water; larger fish seek the depths. Overhanging vegetation provides shade and cover for riverine fish and extra food comes from terrestrial insects that fall into the water.
Get to know your local trees in readiness for when they’ll be of use to you and your aquarium. Find oak and beech trees for leaf and twig gathering. Find alder for those all important cones, which beat any blackwater treatment for staining water brown. The branches of Cherry trees look good underwater, and find out what an Azalea looks like. The roots of Azalea bushes are none other than good old ‘Redmoor wood’. Find dead Trachycarpus leaves in parks and botanical gardens as they look superb in Amazonian themed tanks.
A typical UK minnow habitat perfectly replicates danio habitats in Asia, so reproduce that at home, and your Asian riverine barbs, danios, rasboras and loaches will be very happy.
9 Put some hardy tropical fish outside
This is somewhat controversial, as some fish species could be considered a threat to native species, but I’m talking about true tropical fish species here, that in no way would survive outside in the UK year round.
Hopefully the fact that we are leaving Europe will also prevent the farce that has been banning Apple snails and Water hyacinth from being repeated (South American Apple snails were found to be breeding outside in Spain). And if Theresa May ever wants someone to argue the case for those two species, I’ll happily go to Brussels and negotiate for them on her behalf. I do feel that Apple snails might be low down on the negotiations list, however!
Start by harnessing as much sunshine as you possibly can. That means using black pond liner or plastic which heats up quickly.
Next is positioning. Place the black lined pond or tank in a south facing location. Then there’s insulation. Put the tank in a greenhouse, or build a polytunnel or cold frame over the top of it. It’s all about extending those summer temperatures for as long throughout the season as you can, and preventing rapid cooling at night. Then you need a thermometer to monitor day and night water temperatures, and it would be wise to take the extra precaution of putting an aquarium heater in there too, just to be on the safe side.
If you then do all the usual things such as using a mature filter and monitoring water quality, what’s stopping you putting some of your hardy tropical fish outside if the water temperature is 24°C? Acclimatise them carefully, just as you would when transferring any fish from one tank to another.
I’ve taken lots of tropical fish species outside for the summer over the years and when I bring them back indoors again at the end of the season, their colours are intense from all that green water, live food and the sun on
Get free food with mosquito larvae (above) or breed your own Daphnia (left).
Your Garra will love those pre-prepared green rocks and stones.
Paraguay eartheater, Gymnogeophagus balzani.
Hillstream loach, Pseudogastromyzon cheni.
Moustached danio, Danio dangila.