Eau (or anyone else), what ph for Mollys?

[Marne]

Just lost my only male molly, i'm getted as he was a handsom black Molly . Theres no sign of infection, he was perfect. An hour ago he swam behind the fry net and stayed there a while, i shooed him out a couple times and now i have found him dead on the bottom.

I have also been having trubble with my Molly fry dying (my guppies are fine).

I have tested the water (i now have a proper testing kit) and all is ok appart from the ph being high. I have ordered 'ph down' to bring it down. Could this be whats killing the mollys? What ph would be ideal for them?

[Marne]

Ph 7.4
Nitrate 0
Amonia 0.25
Nitrite 0

[EauRouge]

That pH isn't too high for mollies at all, it's only just higher than neutral. Mollies can go up to 8, they are pretty adaptable. A steady pH is more important than exactly the right pH, although some species are more picky than others. It wouldn't be the pH that killed him.

Don't bother with the pH down stuff, it's very hard to change the pH of water without starting from scratch with RO water. In fact the stuff that brings the pH down can very easily go wrong because of reserve alkalinity- you add it and add it and for ages the pH stays the same, then the reserve alkalinity is exhausted and you get a massive pH crash and suddenly the fish are swimming around in acid and die from pH shock.

If there are no symptoms at all then it could be some kind of internal bacteria. How old was the fish?

How come you are getting an ammonia reading but no nitrAte? That's a bit weird.

[Marne]

Thanks Eau, will rule that out then. I'm not sure whats going on, i have 3 female Mollys in the tank, 2 keep getting swim bladder problems (they seem ok now) and they keep habging around near the heater (temp is around 27-28).

I'm not sure if the amonia is right as the colour was kind of inbetween 0 and 0.25 (so may be closer to 0), i did a water change 2 days ago, the water is clear and all the guppies seem ok (and the fry that are in there).

There wasnt any sign of anything being wron with the black molly, he seemed to be the most healthy one , when i fished him out there was no marks on him at all. I bought him 3 months ago along with a female, the female died a few weeks ago when i had problems with nitrate in the tap water (i lost a lot of fish but the black molly survived).

Dd1 is gutted as it was her favorite fish. I will need to make sure all is ok before i replace him (i need a daddy molly to keep the females busy).

[EauRouge]

It\s weird that your nitrAte is zero, I would expect it to be higher in a cycled tank. When's the last time you cleaned the filter?

[Marne]

I havn't cleaned the filter sinse i changed the media over (when i bought the filter), this was about a month ago and i only lightly squeezed some of the gunk out. I did change some of the media over last week to cycle my other tank (about 1/3), could that have caused it?

[EauRouge]

It might have done, I wouldn't worry too much about the ammonia, but still wouldn't explain why the nitrAte is zero. Are you using any kind of nitrAte reducing chemicals?

[Marne]

I did use nitrate reducing treatment a few weeks ago (when there were high nitrates in my tap water) but only treated the tank once, i have done 3 or 4 water changes sinse. So it could be that? other than that i only use tap safe.

I lost a snail yesterday too (one of my red spotted snails), it was in another tank but its one of tanks i treated a few weeks ago, could this have caused his death?

[EauRouge]

Could what have caused his death? How old was the snail? They don't live very long.

I don't think the nitrAte treatment would still be working. I would expect to see some nitrAte in the tank as it's the end product of the nitrogen cycle. What size is the tank and what fish have you got in there? Which test kit are you using and how old is it? Liquid ones usually have a date on them.

[Marne]

I only got the snails a couple weeks ago (2 of them) the other one keeps coming out of the water.

The tank is 140ltr, has 3 adult mollys, 6 adult guppies, bristle nose (not fully grown) and around 10 fry (some still very tiny), oh and some assasin snails.

The other tank with the dead snail has 1 female fighter, 3 corys and 3 danios and is around 70ltr.

The test kit is new (bought it last week) and its the fresh water master test kit. I will test it again now, maybe i did it wrong (still getting used to the testing kit).

[Marne]

Right, have tested both tanks:

140LTR
Amonia 0.25
Nitrite 0
Nitrate i would say is inbetween 0 and 5.0 (the water is more yellow than orange but theres a trace of nitrate, just very small)

70ltr
Amonia 0
Nitrite 0
Nitrate again is inbetween 0 and 5.0 but is closer to 5.0

Also tested with the strips and both are showing traces of nitrate but not a hge amount.

[EauRouge]

Is the 140 litre planted? Might explain the low nitrAte. Is your tap water also low? 0-5ppm is no problem, the lower the better, but zero is weird.

[Marne]

It only has one plant (not a big one either), tap water was high in nitrate but has now come down.