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Here are our considered answers to your problem enquiries.

We hope that you will find them of value but we can't guarantee success - there are just too many variables in fishkeeping (especially if there's a vital fact you omitted to tell us in the first place!)

If you disagree with our suggestions, or know of a better remedy, we offer you space on these pages for your point of view too.

Click HERE to send your views - help save fish in distress TODAY!


I hope you can answer my question, I have just finished re-lining my new pond, before I put paving slabs down the PH level was 7.5, when I added the slabs a small chunk of mortar went in to water, now the pH level is nearly 9.0.!!

I have added Water plants on Saturday (lily plant, oxygenating week & some reeds) but the pH has not changed. Do you sell a product that will reduce the pH level to 7.5 - and how much? Kind Regards Ben

Don't panic Ben!
pH is a variable through the day and naturally changes from early morning to late evening due to the action of the plants taking out the carbon dioxide in the water (making the pH rise); when testing pH you should always do it at the same time of day to allow for this.
It is odd that a small piece of mortar should raise the pH so much.

It is assumed that you relined the pond with a flexible liner, as opposed to re-rendering the pond walls. In the latter case, the rendering will have needed to be sealed (with something like G4) to stop any lime in the rendering leaching out into the water. The plants you added recently won't have had time to alter the water condtions as they will take a few weeks (and no little sunshine) to become established and growing strongly.

Changing the pH of a pond by adding pH adjusters could be an expensive business.
The quickest way for you to get the pH back towards its earlier value would be to flush the pond through with a hose. If the pH is still high then you should check the pH value of the tapwater to start with - it may be higher than you suspect.


I have family that live in Muncie, Indiana, here in the U.S.andthey have a river called White River. I have heard that catfish have either no fins and/or no gills and I can't remember which. Can you answer please? Thank You, Larry

Well, here's a poser! After much deliberation, we can only conclude that someone's got hold of the stick in the middle rather than just the wrong end. However, there may be tiny grains of truth in there somewhere to give rise to this query.

For instance, our old friend the Clarias Catfish, so given to 'walking' along the canal banks might give non-fishkeepers the impression that it doesn't need gills (it can store atmospheric air in a labyrinth organ behind the gills actually) because of its out of water activities. Because of its body shape it may even appear not to have fins.

Some Catfish have very primitive dorsal fins, sometimes nothing much more than a single ray (Glass Catfish Kryptopterus sp) whilst the closest we can get to gill-less fish might be the Lungfishes - the South American Lepidosiren species develops fine filaments on its pectoral fins which act as supplementary dermal breathing organs.

But other than that this enquiry has us stumped; it's surely one to be thrown wide open to all the visitors to our site. We don't mind, in the quest for the truth, being proved wrong!


I am thinking of investing in a marine aquarium. Which should I choose - a fully fitted tank or go for a tank with a separate sump filtration system below it?

Setting actual costs aside, one deciding factor might be the actual size of the intended tank. A 'fully-fitted' tank will have, by definition, some of its swimming space occupied by 'hardware'; in a modest-sized tank this space could be regained by having a separate sump in which to house the heater, protein skimmer and any other water treatment equipment.

A bonus of a sump is that maintenance can be carried out without any dispruptive intrusion into the main display tank. A slight complication is that the water has to get from the main tank down to the sump and back again which may mean drilling or modifying the main tank plus the 'worry' of the pump returning the water failing. Major water loss is not a worry as the downward flow stops as the overflow weir action ceases due to any failure of water returning to the tank.

On aesthetic considerations, a fully-fitted tank might be cheaper as there is not a necessary cabinet to hide the sump and its workings. Many people would envy your 'problem'!


I have read somewhere that reducing the Specific Gravity of the water in a marine aquarium can help against parasitic infections. How much reduction can the fish take without being stressed?

It is true that a reduced Specific Gravity does cause more stress to parasites and, in many cases, large public aquariums do operate such a scheme especially with new introductions.
By quarantining them in a low S.G. environment, many parasites are removed before the fish are put into the main display tanks. Of course, the added bonus to the public aquarium, is a reduction in salt costs - no little saving when you consider the size of even their quarantine tanks! Generally the S.G. is reduced to around 1.020 from the nromal 'full strength' reading of 1.025.

It is debatable whether such an action is necessary in home aquariums for the simple reason that the fish you buy from your detailer would (or should) have been properly quarantined before being offered for sale and are, therefore, 'clean' and relatively safe to introduce into your own aquarium. Whether you actually follow quarantine procedures with any new purchases or not, is up to you.


I noticed last night that my Plec seems to have changed.
He no longer is fully brown with his odd spots and it looks like he has lost part of his skin
(or whatever top part of their body is).

The only conclusion I have come to is that perhaps my Tiger Barbs have had a go at him when I have dropped a tablet for him to eat at night as they do tend to kind of fight for it and the Plec gets his way so they can't get to it.
Do you have any other solutions as to this problem as I have never seen it before. Ashleigh

All manner of things can happen during the night and it is not unusual for some fish to emerge into the daylight with bits of fins missing. The problem is finding the culprit, of course, and this can throw up some unsuspected results.

The Yellow Tetra, Hyphessobrycon bisfasciatus, for instance is a good example having been known to tear off all the dorsal fins of Corydoras Catfish in its tank.

Your Tiger Barbs may well be the culprits but there could be another explanation: if, in his actions the Plec tries to escape the attentions of the Tigers, he may well attempt to hide from them underneath something - have you thought it might be burns from an unguarded heater or scratches from some sharp rockwork? Just a thought.

You might try feeding a less localised (but still fast-sinking) food after lights-out. Granules or 'wafers' might spread the other fishes' attention away for long enough for the Plec to get his midnight feast in peace.



Have been trawling through quite a few web pages to try and identify British native oxygenating plants for a very large pond with a good head of fish.

Last summer I had a lack of oxygen and most of the fish were in difficulty, only resolved by putting in an aerator. Do you have any info on plants that are not too invasive and most importantly, NATIVE BRITISH PLANTS?
Regards, Ken Whitley

Isn't it typical that there are so many knock-on effects in fishkeeping?
You put in a filter to get clear water and the next thing is an unwanted abundance of blanketweed! It's the same with oxygenators - you put plenty in but when the hoped-for warm weather comes along the oxygen levels plummet overnight due to the plants not photosynthesising.

Native oxygenators include Hornwort, Ceratophyllum demersum, Water Milfoil, Myriophyllum spicatum and Canadian Pondweed, Elodea canadensis (an introduced 'foreigner' but it can't be ignored).

Another small-leaved plant is Willowmoss, Fontinalis antipyretica, which bushes out rapidly and provides a good spawning receptacle for both fish and amphibians.

All of the foregoing are floating plants needing no rooting, but there are larger-leaved plants which do need anchorage. Curly Pondweed, Potomageton crispus, has shiny, bronze/green leaves whilst Water Hawthorn, Aponogeton distyachos, has long oval, surface-floating leaves and vanilla-scented flowers too.

Of course, the Water-lily does a fine job in shading the pond, absorbing nutrients from the water and providing wonderful flowers as well. There are two native Water-lilies, Nymphaea alba, a vigorous-growing white, and the Brandy-bottle, Nuphar lutea, although the latter whilst attractive with its bright yellow buttercup-like flower is often too vigorous.

Speaking of vigorous growth, the only way to restrict rampant growth (apart from continually raking out floating species) is to growth any rooted plant in conatiners. A good layer of mud or silt on the pond's base only encourages plants to spread!

Incidentally, there are strict laws about taking plants from the natural environment; you should be able to get native aquatic plants from aquatic plant specialists.



I was interested in what causes the colouration in Goldfish.
The reason being, is that I own 2 Common Goldfish.One male and one female.
They both started off the normal orange colour but now are losing their colouration to be a white colour.As far as I can tell they are not diseased or ill.I have been trying to find out why they are changing colour and have not found a reason for it yet.

My male Goldfish has been orange for quite a few years but over the last few weeks since i have changed tanks, has been quickly turning white. They are both fed on the same food and have been for several years now so I know it is not that.The only changes to their environment are:

- the heat of the water (due to a fluorescent light being present now)
- the lighting (as they did not used to have a light source, just in a dark part of a room
   away from windows)
- Chemicals added to the water to take out the chlorine.

So I was wondering if you had any ideas as to why my fish where changing colours.I would appreciate any help in this matter. Regards, Samantha

Hi Samantha,

Thanks for your question and for your interest.
Goldfish do tend to gradually lose some of their colour as they get older but, from what you say, it appears that the colour changes in your fish have happened rather rapidly.
The change in lighting and temperature could have some bearing on this, or it could even be that your fish have gradually lost some colour and this has only really become noticeable now that you have increased the light. I would very much doubt that any good quality dechlorinator would affect the colour of your fish.

Silver or white colour in Goldfish really denotes a lack of colour pigment rather than a different colour. It means that the lipochromes (red and yellow pigments) decrease within the fish, leaving the silvery white of the guanine to show through.

Loss of colour in itself should not be a problem to the fish but, occasionally, a fish will lose some of its colour if it is stressed. It would be worthwhile testing the tank water to ensure correct levels of ammonia andnitrites and check the pH (acidity / alkalinity) of the water
(a pH anywhere between 7 and 7.8 should be fine).

Check, also, the behaviour of your fish.
Are they eating normally and are they as active as they normally are?
Do they show any signs of gasping at the water surface or flicking themselves against rocks or gravel?

If none of the above shows up any irregularities, then I would say that your fish are, as happens to all of us eventually, simply 'going grey' as they get older.
I hope this is of some help to you.


We have just purchased two mixed Oranda fish and placed them in our newly erected tank.
I have a couple of questions I need answering.

Question 1) Our tank size is: Depth 24cm x Height 38cm x Width 37cm.
                  The fish are approx. 6-7 cms in length (excluding tails).
                   Is the tank a sufficient size for these fish? They are the only fish in this tank.
                   We appreciate that over 4-5 years they may eventually out grow this tank, but is
                   the tank a sufficient size during their early years?

Question 2) Both fish have tears/rips to the Caudal fins, which we didn't see
                  when they were purchased (although they may have been there but went
                  unnoticed). Is this normal? Will the fins repair themselves or grow again?
                  How could this have happened? Would they have bitten each other or have they
                  been snared by the filter tube? I'm sure it is nothing too serious as the fish have
                  settled in really well and are feeding and swimming around happily.

Question 3) We have been advised that the Oranda fish generates a lot of waste and to
                  assist with the cleaning up process we should invest in one or two algae eating
                  fish. Is this wise and will this also max-out the tank again adding to our over
                  stock concerns?

We would appreciate a swift reply to alleviate the concerns we have,
Kind regards Paul & Sandra Wells

It is gratifying to find such a caring attitude in new fishkeepers, it can only augur well for the future.
Your aquarium seems adequate for these two fish but they will probably need larger accommodation after a few years, as you suspect.

The fin damage could have been caused simply during handling, transportation from the dealer's and introduction into your aquarium. Bear in mind that the very nature of the Oranda's fins that appeals so much to us visually is due to the fins delicate structure; this is why such Fancy Goldfish are much more suited to the indoor aquarium rather than the outside pond (we can see them much more conveniently too).
Just as a precaution (and especially if the split fins do not heal up soon) try giving the fish a treatment of Melafix. This remedy is readily available from your aquatic dealer and can be highly recommended.

You will see from earlier queries in these pages that damaged fins are an open invitation to secondary disease, particularly if the aquarium water conditions are not of the highest quality. I notice that you have a filter in operation, which is good. Do make sure to carry out regular partial water changes one or two gallons every two or three weeks and, when rinsing out any filter medium, always use some aquarium water to do so, not new tap water. This will maintain a colony of helpful bacteria within the filter and not set it back too much in its efficiency.

Please do not add algae-eating fish to help clear up the tank's leftover food. You can manage the amount of food quite simply by only giving what the fish will eat in two or three minutes; algae-eating fish rarely fully live up to their reputation and eventually start harassing the other fish. It is difficult to imagine what species you have been advised to stock with your Orandas hardly any genuine coldwater species comes to mind that would be suitable and a tropical species would be out of the question. Also, as you have already surmised, another two fish would be pushing the tank's fish-holding capacity to the limit.

From your other remarks, it seems as though your two fish have settled in really well, it would be a pity to spoil such a beautiful beginning. If you have any further worries or doubts, please get in touch with us but, in the meantime, enjoy your fish!



I was reading the answer to the plant query about 'British Oxygenators' on your pages and noticed that one plant had the word 'antipyretica' in its scientific name.
This, I take it, means 'fireproof' but how does this square with an underwater plant? Puzzled of Peterborough

You're not only observant but quite right too, Puzzled.
The plant's specific name (Fontinalis antipyretica) does indeed mean 'fireproof' and it is a story that goes back hundreds and hundreds of years.

Apparently, houses' eaves were stuffed with the plant (which has non-inflammable properties - you don't keep having to wet it down!) to form a firebreak probably to stop the rush or thatch roof from catching fire. Whilst it is said to date from Roman times, apparently Eastern European and Scandinavian people also found it useful - long before us fishkeepers got interested inthe plant for a more natural reason!


I set up a reef tank (Berlin style) a few months and am quite pleased with the results so far. I am a little alarmed by the sudden appearance of 'anemone-like' growths on the living rock. In their own way, they are not unattractive but they seem to be increasing in numbers.

I appreciate that when you use living rock you take a chance on 'stowaways' and hope that any that do come to light will be benign rather than malicious.
What ought I to do about these creatures? Brian

As you say, you are at the mercy of living rock's passengers which can, at times prove troublesome.

What you have been blessed with is the Glass, or Rock Anemone, Aiptasia and these can be hard to eradicate. However, they can be kept under control by both natural and 'man-made' means.

It's no use prising them off from the rock as any remnant will simply regenerate.

Physical methods that have been tried include buring them out with a soldering iron, injecting them with many things such as boiling water, lemon juice and kalkwasser. There is a proprietary brand on the market called Joe's Juice which is reported to be efficacious.

Turning to natural predators, the most favoured are an invertebrate and a fish. The Peppermint Shrimp, Lysmata wurdermanni, is fond of eating juveniles and perhaps harrasses the larger specimens too.

The Copperband Butterflyfish, Chelmon rostratus, also eats Aiptasia and you can imagine how the fish's elongated beak-like jaws are brought into play in this respect.
One problem of using this fish is that it may be difficult to keep for the inexperienced hobbyist, although some report that it is troublefree.


Last updated April 8th, 2005