dying fish consistent problem
I'm looking for theories on why most fish don't survive long in one of my tanks.
100 gallon, slightly overstocked maybe, but then so are my smaller tanks.
Under 50 small fish.
Tank started 6 years ago.
Problem started after only a couple months.
I have 5 long term survivors, 5 plus years.
Glass bloodfin, rummy, celestial danio, panda garra, hillstream loach.
fish die with various symptoms, some have cataracts, some do spinning, fast breathing, dropsy, swim bladder, tumors, red streaks, and overnight deaths, etc.
I currently have 3 male furcata rainbows with swim bladder and scoliosis issues.
Females from different store look good so far.
Lost a 2 year old killi last month got very slight looking whitish upper tip sinus area and then fast breathing, refused food.
kanaplex didn't help.
I do weekly 50% water changes.
use 25 watt UV a few hours a day, heats the tank too much to keep on.
2 canister filters, monthly cleaning, but only removed the hoses to clean twice.
Gravel vac every other week.
many somewhat healthy plants, no CO2 discontinued a few years ago too many fish deaths.
neutral soft water from tap.
I've in the past tried various antibiotics to try to kill possible bacteria.
Taken out a lot of gravel so not as deep as I originally had it.
Good water flow, don't think there are any dead spots, removed all wood and rocks.
I wanted an aquascape, now a very plain tank just trying to keep fish alive.
What are your exact water parameters? I once had a nitrite issue and it was coming from my tap water!
Do you quarantine new fish, and if so, for how long?
I am going to assume you have good test kits. Such as the kind that requires you to add drops of reagent to a glass test tube and that your test results are ok.
So with your years of experience, I will go directly to what I suspect first.
I think you may have a trace or small amount of electricity getting into the water either from your pumps or maybe the UV or by induced current from your lights being too close to the water surface. If you are familiar how a transformer works, then it about the same. If a core with many wraps of wire is placed next to another core with more or less wraps and an current is applied to one of the core wires, then the other core is affected by the electromagnetic field and creates a lower or higher voltage. Now this is a possibility in your case.
If my suspicions are correct, then I would start first with the UV and stop using it. If you have a voltmeter, set it for 50 volts or less and attach a grounding wire to the screw of a electrical receptical. Place one voltmeter lead into the water and the other on the grounding wire (keep your fingers away from the metal part of the leads) and see if you get a reading on the AC and DC scales. write down the voltage no matter how small. If you get a reading, then you need to test all equipment that uses electricity by shutting them off, one at a time to find out which one gives the highest reading. Don't forget the heater.
To date, I do not know of any research performed on how much induced current it takes to affect the health of aquarium inhabitants. Many years ago, there was a discussion on another forum about it.
I tested my water back then and got a reading and my tank was grounded which I suspect made it worse because it created a path for the electricity to flow.
The other suspicion which is much easier to correct is how you vacumn your gravel. Some fishkeepers say that if you push the pickup tube below the surface, it disturbs the nitrifying bacteria and pulls it away from the gravel and an ammonia spike can occur. By the time you test the water, the spike has been corrected but the effects on the fish are apparant. I am not sure that theory is correct but to cover myself, I use a product that adds nitrifying bacteria when I vacumn every two months.
Another thought along the lighting lines.. Is the UV the only light source? Perhaps the fish (and the plants) aren't getting enough light?
Here is an interestion read on the subject of stray current in the aquarium and the following content is made available under Creative Commons Attribution - Share Alike 3.0 Unported License.
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Stray current refers to unintentional electricity flowing through the aquarium water. Malfunctioning and deteriorating equipment are the usual sources and can represent a danger to the aquarist and livestock. Stray current is closely related to stray voltage - a voltage potential between the aquarium water and ground.
In typical household circuits, current is far more dangerous than voltage.
Stray voltage is an electrical potential difference between the water and earth ground. A voltage difference does not indicate any electricity is actually flowing through the water. It indicates the possibility of current to flow if a suitably low resistance path between the water and ground is introduced. So stray voltage on its own is not directly harmful. It is common to have some stray voltage as pumps can induce a voltage potential with their rotating magnets.
Stray current refers to flowing electricity. It should be considered dangerous at even the milivolt range. When wet, the body's electrical resistance is dramatically reduced allowing more current to flow. At the 100ma range, current can cause ventricular fibrillation (uneven, uncoordinated pumping of the heart), muscular contraction, nerve damage, death is likely . A properly functioning tank should not exhibit any measurable stray current (< 1mA). Stray current may or may not trip a GFCI receptacle depending on the path it takes.
An energized conductor is exposed to the aquarium water. This usually occurs when equipment is worn or damaged. For example, an electrical cord where the insulation is cracked or worn away. Other examples includes cracked housings on pumps and heaters. This is dangerous as the full current of the outlet may flow if the aquarist touches the water and a ground (like a grounded metal fixture). In rare cases, under the right circumstances (Murphy's Law), when there are multiple electrical cords/components in the water (which is the case with most of our systems), there is the possibility of current flowing from Line to Neutral or Ground from one cord to another. This current will flow from one component to the other, through the water & may not necessarily be measurable with a meter to ground. It will most probably affect your livestock though.
Moving magnetic fields can induce a voltage and current in the aquarium water (or any conductor). Pumps and powerheads often have spinning magnets and may generate up to 50v of voltage but only very small amount of current. Flourescent bulbs (PC, VHO, T5) will also induce voltage and current. The current induced by these sources is small, in the nanovolt range .
This may possibly be a small source of stray voltage. The large conductive surface film will likely dissipate any charge.
wow, really cool theories, I will get on these tests tomorrow.
I don't have GFCI.
I've only replaced one of the filters.
so, a lot of the equipment is original.
I have an inline heater, a powerhead at the bottom for more water movement so there is a cord submerged, and compact flourescent lighting close to the water.
The UV I added about a year and a half after starting the tank.
Nitrite, can't remember if I ever checked the tap water for it, but I have checked
after a water change in the past.
I don't have trouble with my other tanks though.
Lost interest in testing, since always checks out good.
have several different brands of each test to make sure no issue with test quality.
I have not checked for ammonia after gravel vac as far as I remember, always tested after water was replaced and before cleaning.
The idea about current is something I haven't thought about.
Very interested to see the result.
Thank you very very much!
the suspense was killing me so I checked for current just now,
Underwater powerhead and nightlight LEDs do not put out current.
Every other single device puts current into the water.
With everything on the reading is .027 using a digital multimeter set at 3
I don't know much about electricity.
filter .004 both running becomes .005
.030 inline heater, on or off
all items plugged in and running .027
So, scrap the heater and use the UV for heating for now.
Will have to see how the other tanks test out.
Thank you so much!
with the inline heater gone reading is .017
checked my other tanks one had a heater which caused a reading of .011
Scrap the one heater and now the 3 other tanks have a reading of .004
Are these readings ac or dc? Some of the equipement we use operates either on ac or dc. My pH meter has an adapter that converts ac to dc. My led's have an ac imput but operate on dc. Aquarium pumps and powerheads are ac operated unless they have an electrical adapter. So some of your readings may be in error. The author states that current produced by Flourescents, T5, Pc and VHO produced currents in the nano range and we need not worry about that. He suggests that we should not get any readings above 0.001 amp or 1 milleamp. But if all the equipement is reading higher, then I would suspect its normal unless the equipement is old and possibly deteriorated and the authors suggestion may be questionable. We need to find out more by everyone testing their water for current as outlined in the authors directions. Then we will know what is normal; a little current or no current. I think this is a subject that the manufacturers do not want to touch.
In the end, having a gfci to protect you is a good idea, but using a grounding rod in your aquarium creates a path for current to flow when it occurs and is not a good idea for the tank inhabitants.
The differance between the two is that the ground rod may have a current flow that is less then what a gfci can detect. So the question is: how many milleamps is that and is it enough to affect the tank inhabitants?
I forgot to ask. Are your readings in amps or milliamps? If its milliamps, then you should be ok.
I just tsted my water for both ac & dc current and got zero. But My equipement is only 1 year old. I tested with a meter that can read down to microamps. So I assume I am ok. According to the author, anything less then 1 milliamp is ok.
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