Lots of great new fish foods in stock!

We have always kept a good variety of fish foods available on our website including many of the top brands.  And we have always offered a handful of foods that we have been able to buy in bulk and re-package to bring our customers great savings while not sacrificing quality.

The re-packaged foods have always proved popular and for the past several years we have been searching for a source of bulk foods in order to increase our customer choice. We are really pleased to announce that we have found a reliable manufacturer who is able to deliver consistent shipments of high quality foods that we can offer to you at an amazing value price!  These include very specialist items like freeze dried whole fish to general community complete stick on tablets.

We will be sending out samples with every order along with a fact sheet about the foods.  If you want more information in the meantime or would like us to send a leaflet, just drop us a line on sales@dlsaquatics.co.uk.

If you try any of the foods we would love to hear from you in the comments below!  Don't forget to use the discount code JAS13 to receive 10% off your order!

Understanding the water your fish live in, from Keith's Corner

Today Keith is going to talk to us about water, not as simple as it sounds!

Keith Jackson is a retired engineer who has been keeping tropical fish for 40 years and a pond for 11. His first love is the South American family of small catfishes of the group Corydoradinae, covering the genera Corydoras, Brochis, Scleromystax and Aspidoras.

Is there anything sillier than reminding fish-keepers that their fish live in water? Jackson’s cracking up, you say (and you won’t be the first) but it’s worth remembering this somewhat obvious fact and considering its implications for our pets.

What we think of as water, that clear liquid coming from our taps, has been treated and purified before reaching us to make sure that it is safe for us humans to drink but what’s safe for us isn’t necessarily safe for our fishy companions for quite a number of reasons.

In an earlier blog I mentioned the nitrate cycle and said that it functions through several types of bacteria. Tap-water is made to be hostile to bacteria, by the use of chlorine or, more recently, chloramine, and adding water straight from the tap is likely to damage the bacterial population of the filter, potentially leaving too few bacteria to complete the nitrate cycle and stressing the fish. There are many brands of de-chlorinator available from aquatic shops and I’d recommend their use. As I change hundreds of gallons a week in my pond and fish house, I use a commercial carbon filter that fits onto a tap using standard hose fittings but the effect is the same.

That is an important factor but it’s far from the only thing we have to consider. Our fish come from all over the world and the freshwater fish most of us keep – marine fishkeeping is another matter entirely – have evolved to live in an extremely wide range of environments. I’m not thinking of the difference between lakes and rivers but between the rocks over which those waters flow. Some of the rocks in South America are very old and any soluble material has long gone so the more-or-less pure water that fell as rain is in much the same state hundreds of miles downstream. This is water that is very, very soft so its pH – acidity and alkalinity – is easily changed. Passing through some of the most fertile forests in the world means that vegetation falls into the water all the time and, as it rots, it makes the water acidic.

This is the type of water that is home to two species of the Discus cichlid: Symphysodon discus and Symphysodon aequifasciata. They are extremely beautiful, even in the wild forms that are rarely seen these days, and large discus are a true sight to behold but they can be a nightmare to keep. They just cannot deal with even medium-hard water so fish-keepers need to provide not only a large tank – these are almost circular fish that can grow to more than 6 inches/150mm across and need to be in a shoal – but also the soft water they need to thrive. It is possible to strip salts from tap-water using resins, though not conventional water softeners, but the trend these days is to use a reverse osmosis kit. If you’re on a water meter, my advice is to forget discus. It’ll cost you an arm and a leg to buy and run an R-O kit!

At the opposite extreme are another family of cichlids that come from the Rift Valley lakes in Africa, such as Lakes Nyassa and Tanganyika. Here the water is so hard you could almost make bricks from it. Again, water from the tap is quite unsuitable and where you have to remove salts for discus and make the water acid, for these fish you have to add salts and make the water strongly alkaline. Do that and you will have a display of fish with amazing colours but don’t and they’ll simply sicken and die.
Luckily for us, most fish offered for sale don’t need such extreme conditions and will survive quite well with a medium hardness and a pH between 6.5 and 7.5. Breeding may be a different matter but they will live happily enough.

You knew there was a ‘but’ on the way, didn’t you?

Although most fish can tolerate hardness and pH levels rather different from their waters of origin what they can’t withstand are rapid changes, especially in pH. That’s because they don’t live in air.
Jackson’s gone bonkers again!

No he hasn’t. One of the adaptations that allowed our distant ancestors to leave the water behind was the evolution of a skin that was impermeable so that our internal water stays there. As a result, we don’t dry out, as amphibians can because their skin, like that of a fish, is permeable so they have to keep themselves damp. Water is both inside and all around a fish so there is no need for an impermeable barrier but that means water moves across the skin layer all the time – by osmosis – and the fish’s organs have to balance that. A sudden change throws that out and the fish will be stressed until it has achieved balance again. If you need to make a change, do it slowly.

When I started keeping fish, in the 1970s, it was an accepted fact that you had to make the water you used to change your tank exactly the same temperature as that in the tank or you would kill the fish. For years I would boil kettles and mix that with the cold water in my buckets but no more. Why? Because it is nonsense! I change 25% of the water in my tanks every week and use water from the tap, through the carbon filter and into the tank. I run it in slowly so that the new water can be dispersed by the water flowing around the tank but I don’t heat it and I’ve never killed a fish. I may even have induced some to spawn as some species are triggered by the cool melt-water coming off the mountains in Spring and chilling the water that they’ve been living in by 5 °C or more. Where did that myth come from? Goodness knows but it was widely held at the time.

One final thing: tap-water varies across the country. In Derby it comes from the southern Peak District and has some hardness but not too much so I rarely have to descale anything. Twenty miles away, my father’s water comes from boreholes near Burton on Trent and has a lot of gypsum in it, which is great for brewing but leaves lots of lime behind in his kettle. Around Wigan, the water is very soft and friends can keep discus with ease but have to spend a fortune on salts for any Rift Valley cichlids they have.

So I hope I’ve made you think a little differently about water. It’s a lot more complicated for us fish-keepers than outsiders might think. The crux of the matter, though, is that you need to know not only what your fish need from their water to do well but what is in your water, too.  Get the water right and your fish will thrive. Don’t bother and you’ll be simply chucking your money away, along with the fishes’ bodies.

The Spring Pond

Today we are really pleased to bring you our first guest blog from a fellow member of the Derby and District Aquarist Society, Keith Jackson.  He will be taking us through his experience of The Spring Pond.  

Keith is a retired engineer who has been keeping tropical fish for 40 years and a pond for 11. His first love is the South American family of small catfishes of the group Corydoradinae, covering the genera Corydoras, Brochis, Scleromystax and Aspidoras.  He has promised us a future piece on this subject.

From Keith:

After a particularly cold Winter, my pond is emerging quickly, just as the Spring bulbs have rushed into spectacular flower in our garden. Although things have been delayed this year, Mother Nature is doing her best to get back on schedule.

My pond is about 2m deep and 2.5m in diameter, about 2,000 gallons or 9,000 litres in capacity, and I inherited it when we moved to this house in 2002. I keep mostly koi but there are a few goldfish remaining from when I first set it up again. Not that the goldfish are particularly overawed by the koi as they are pushing  30cm body length and seeing the colours and flowing fins of Sarasa Comets moving around certainly adds to the spectacle, even though I probably wouldn’t include them if I started again today.

Around this time of year, most pond-keepers will have an outbreak of algae. It may arrive as green water so opaque the fish are like ghosts or as long strands that make swimming difficult and get entangled in pumps or, indeed, as any combination in between. Sometimes the growth of the algae is incredible and the keeper can easily despair of getting rid of it and he or she tries to remove it physically. It seems like a never-ending task. So what causes such outbreaks? That’s simple. The presence of chemicals that the algae can feed on, which leads us to what’s often called the Nitrogen Cycle.

All fish eat and excrete but fish, unlike humans, release Ammonia as their liquid waste. When you think about the waters fish come from, whether it’s a lake, stream, river or the sea, the volume of water is huge or it is flowing quickly enough that the fishes’ waste products are diluted rapidly and the fish don’t suffer. A limited, static volume of water, like a tank or pond, is quite a different story and we all keep a much greater density of fish per unit volume that would be natural in the wild. Ammonia is highly toxic to fish and it is the reason so many new fish-keepers, given bad advice by shops more interested in profits than the welfare of the animals, give up when they lose their fish in no time. So what can we do?

It would be very difficult and expensive to simply flush the ammonia away so we use a filter and hope that it will develop the bacterial cultures we need to keep our fish safe. These cultures take time to reach an optimum level and the development time is the reason responsible shop-keepers only allow newcomers to add fish gradually to the new aquarium or pond. There are two groups of bacteria involved. One uses ammonia as a food source and releases nitrite compounds and the second takes that nitrite and releases nitrates. All three are toxic to fish but the relative toxicity reduces along the cycle so fish can tolerate far higher concentrations of nitrates than ammonia. Nevertheless, nitrates are toxic and regular water changes are vital to keep your fish in the best of health. That and the use of a test kit so you can see how well your filters are coping. Once established, you should find no ammonia, trace amounts of nitrite and some nitrate. If the numbers are suddenly different then you know there is a problem to be traced and fixed.

Any gardener knows that nitrates are commonly used as fertilisers and algae are aquatic plants that enjoy nitrates every bit as much as your prize flowers and vegetables. That’s why algae appear in ponds in Spring: there is food available to them and an environmental niche to be colonised. To minimise this problem there are a number of things we can do:

Routine maintenance. Once the weather starts to warm up and the fish become active I restart my weekly water-changes – about 5% - and clean out the brush chamber of my filter. I always check the pump is clear of any algae strands or dead leaves so the flow around the system is kept up.

Feeding. The best tool for an aquarist or pond-keepers is their eyesight. Get to know the normal behaviour of the fish so you can quickly see if any are unwell. If you feed them, are they eager to take it or do they peck at it and leave the rest? If it’s the first you can feed them again later. If it’s the second they’re not yet ready to take the amount you’re giving so reduce it until they do take it eagerly and then build up the amount gradually.

Ultra-violet Lamp. Algae that cause green water are killed by ultra-violet light but you need enough power to kill the algae passing through the system. For my pond, I found a 33W lamp was too small and now use a 55W instead and I leave it switched on all the time, even in Winter. Tubes should be replaced every Spring as their output declines and they will be less effective in Year Two.

 Green water is not a problem for fish. They will strain the tiny particles of algae out using their gills and eat it. We buy it, as spirulina, as an additive in fish food!  But if we want to see our babies we need to deal with it.

Algicides. There are a number of potential problems with algicides, not least because they are not
equally effective against the hundreds of possible species that we can find in our ponds. One that might work one year may not the next because it’s a different alga. It might kill off the dominant type but not be able to do the same to the species that takes over the niche a couple of weeks later. We always have a fight on our hands!

      So is there an answer?

      Basically, you need to minimise the amount of nitrates available to the algae. In other words, the best way to getrid of it is to starve it. I am lucky to have a waterfall into which I can put water-tolerant plants, such as the water grass Glyceria and the Mimulus or Monkey Musk flowering perennial, and they take up a lot of nitrates themselves. The problem with simply relying on that is that the higher plants start to grow well after the algae can get going so I use an algicide based on extract of barley straw to control the algae until the plants take hold and keep things in balance naturally.

      If your pond doesn’t allow you to use plants as a vegetable filter, you will need to keep the nitrates in check by changing more water and testing the water regularly to make sure you keep things in balance. At the end of the day, fish are a responsibility, just as much as a cat, dog or budgie, and we owe it to them to keep them safe and sound. Do it well enough and they might even spawn for you. You never know!

     

      Keith