We have a 37 or 40 gallon tank.

Water readings are perfect to near perfect API liquid test kit. For two months perfect readings with the exception of 2 weeks ago when the nitrate read one step above "0" for no more than a day. Water tested 2x week minimum to 5 times a week max.

Nothing new added recently. Platy's were in the tank for a couple months.

50% water changes weekly with new water being treated with prime and brought to temp over a 24 hour period with separate heater.

Feeding every other day, flake food and once a week dry bloodworms.

Last week on the the red wags was looking like she was pregnant. Then she started to hide i the plats, caves, etc which was unusual. The next day she was belly up.

Over the weekend another red wag started hiding in the plants, caves and last night, it was belly up.

No marks on the fish (no ich, no raised fins, no bulging eyes)

What could be a cause for both of them dying? So far I see no problems with the other fish and the water/tank can't be any more perfect as far as I can see.

Hello jim...

Without the benefit of lab tests, you can't know for sure if anything is wrong with your fish. As far as I can read, you're a good tank manager. Large, weekly water changes will keep the water stable and that's the most important thing for your fish.

You really don't need to age your replacement water. As long as you're removing the chlorine, chloramine and ammonia it can go right into the tank from the tap. Just adjust the temp so it's within a few degrees of the old water. I prefer to make the replacement water a little warmer, about 80 degrees compared to the normal 76.

Raising the temperature in the tank to about 82 degrees for a couple of weeks can help tropical fish. I also use a little standard aquarium salt in my Livebearer and Corydoras tanks. A teaspoon or so for every five gallons of water change water will eliminate most fish pathogens if that's the source of the fish problem.

The combination of a little salt, a lot of pure, treated water flushed through the tank weekly and the warmer temperature will, IMO, strenghten the fishes' immune system.

Just a thought to consider.

B

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Low Tech Water Building Keeper

Were the platys that were hiding breathing heavy and listless?

If so they were stressed. could be ammonia/nitrIte or chlorine or even low pH indicating high carbon dioxide.

my .02

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fw leiden since 1979, fo salt since 1979, mixed reef 55g 2002-2009. Strong emphasis on the tank taking care of itself. Balanced with plant life, no water changes, tap water, no filters in FW. Only dosing calcium, alk, mag in marine reef tanks. http://www.aquariumforum.com/f15/my-...ods-26410.html
recent tanks (till 2009) 7 years- 10g FW leiden 7 yrs, 55g mixed reef 7, 2 yrs, 20g FW leiden, 10 g fw leiden , 29g mixed reef, current tank 55g leiden

They were just hiding.

Ammonia and Nitrate readings have been steady 0 for a long time. Chlorine is eliminated via Prime and letting my exchange water sit for 24 hours. pH, if I remember correctly is steady at 7.5.

I've been keeping platies and swords (very similar) for a while, and sounds to me like they were pregnant. I've lost a few due to pregnancy complications. Generally the female will hide and be seclusive like she was gonna give birth, and then be belly up the next day. It is especially common if platies are kept with swords, as they can interbreed, but due to the larger size of swords it often kills the mother. If this is the case it was probably in the same tank with a sword at the pet store.

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29g Tall FW: Many Swordtails: 1 lemon, 6-8 neon/pineapple, 1 Gold Tuxedo, ? fry; 1 Clown Pleco; 3 Otocinclus Cats, and MTS.
Planted: Amazon Swords.

The only place where success comes before work
is in the dictionary.

i would think it to be odd that your not getting any nitrate readings at all

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10g- 2 hi-fin fm platys, 3 koi & red wag sword fry
40g Breeder- 6 danios, 4 female swords, 1 male swords
"I was born with nothin and I still got most of it left."- Seasick Steve