Rasboras - Harlequin

[Ob1]

cleaned my filter two day ago, yesterday one of the two new Harlequin kept skimming the top of the water and stayed there the rest carried on normally.

all other fish seem fine, angle as come to the surface chasing bubbles from the air stone, I think.

However one new Harlequin died - never found the body? One of my older Harlequin is now doing the same thing - skimming the top.

have changed water today 10-15% after taking some test

Current - Last Week
PH 7.60 - 7.60
Nitrite 0.10 was 0
Ammonia 0.10 was 0
Nitrate 50.00 was 5 double checked

played around with my timer yesterday, and the light did not come on today until 4.45pm. temp 26-28.


any ideas, would not like to loss anymore fish

 

[Lateral Line]

>>> cleaned my filter two day ago

Did you clean it to well? What I mean is, have you destroyed the bacteria that maintain your nitrogen cycle? What kind of filter, and how did you clean it?

Keep your eye on the nitrogen readings and adjust your water changes accordingly.

 

[Ob1]

I have a sponge filter, I collected some water from the tank a cleaned the filter in it.

The water pressure is back to normal, however was my first filter clean... the filter returned to its original colour, however did complete the task quickly might not have cleaned it completely

 

[Lateral Line]

>>> might not have cleaned it completely

That's GOOD!

Your approach to the clean is fair enough, but when you are cleaning filters you must always remember, the filter has 2 purposes, to clean, (mechanically), the water, and to chemically clean the water. The sponge will become home, as you cycle your tank, to colonies of bacteria which convert your fishes waste products from toxic->less toxic->relatively harmless stuff, (relatively, you change water to get rid of this).

If you really clean your sponge, you could have washed away a good number of these beneficial bacteria, hence your nitrogen readings rising.

With sponge filters, if space allows, try to run 2. Clean alternately so the other can cope with the transients introduced by the clean of the other.

Be very aware of your nitrogen readings, (ammonia critically, nitrite importantly), if they continue to be elevated, up you water change frequency and get them down, they will kill, ammonia quickly so.

 

[Ob1]

Have lost another 2 Harlequin this morning.

Any Ideas???

 

[EddieW]

Harlequin's can be very sensitive to water parameters - they don't like changes at all. This may have been a factor. Also Harlequins need to be in a shoal otherwise they will die off.

Get your water parameters back to normal - Lateral Line's suggestion of adding a second sponge filter is a great idea. A sponge filter should never be cleaned back to its original colour as you will have removed all of the good stuff. Just rinse it enough to remove loose dirt and debris, don't try and get it pristine again.

Once you have the tank settled get some buddies for your remaining Harlequins, they will really appreciate it. I have a shoal of eleven now and they are much more active than when there were just five.

Harlequins also need heavily planted areas for shelter, especially at night.

HTH, Eddie

 

[Ob1]

thanks EddieW

will re-test water day, hope fully no more will die. will allowing the water parm to return to normal in the mean time I will set up my spare tank ready for some new additions.


thanks again

 

[Ob1]

and thank you Lateral Line

 

[Lateral Line]

Hope you get it sorted - Rasbora heteromorpha has always been a favourite of mine.

 

[Ob1]

Lost a total of 4 now, and the last one looks like it is going to the same way.
Very frustrating.

Have now started to set up my quarantine tank it only 24inch, however it will hold my next lot of clowns or harlequins not sure which one to go with.

Will have to wait until the tank cycles.

 

[Lateral Line]

I just noticed this...

>>> 42X12X18 Tank 30g

... (I'm assuming these are "Inches"), that´s quite a big tank for a simple sponge filter. Can you tell us a little more about your set-up, in particular, about your sponge, and about any other filters/whatever you have.

 

[Ob1]

I inherited the tank from a friend at work, he had the tank and the same fish for 7/8 years.

I've had it for two weeks lost all his orginal harleqiuns plus the three I added.

Have recently added an ornament to the tank, large one and moved most of the rocks, removed some plastic plants - the tall ones

There is only one filter it 10inch high in total and it as a fast/slow slider just above the outlet hole.

The sponge is a single cylinder type coloured light blue. Have been adjusting temp however always stays within 25-29 at present 28

my Nitrate went from 5mg/l to 50mg/l after filter clean, they are now back to 5mg/l

Notice Phosphate quite high 5mg/l however this is down to overfeeding and have been unable to locate some of the dead fish.

Yesterday I purchased a fluval 4plus, I was intending to run this in parallel to my orginal one for a number of weeks, with a view to removing the old one. I notice the Fluval has two compartments which contain filter material - hence in furture I will change only one half at a time.

Ps every time I change water - which I have done maybe 4 times in two weeks I clean the bottom of the tank to remove byproduct.

I just noticed this...

>>> 42X12X18 Tank 30g

Lateral Line and EddieW
I really appreciate your help, cheers


Current Readings
PH 7.60
Nitrite 0.10
Ammonia 0.0
Nitrate 5.00
Phosphate 5.00