Dead platy & molly in new 6 gal set-up

[jlinsey]

We set up our Eclipse 6 on Christmas day, added decorations, plastic plants and a platy and a molly 2 days later. Three days later the molly had babies, at least 8 of which are still alive and growing. Three days later, the molly looked bad. It had one swelled eye and white under the mouth and died. That evening, after about 2 hours of awkward behavior, the platy died. The baby mollies, 7 of which are protected in a "playpen" are still fine. We replaced the original fish with another platy and a tetra. I didn't know at the time that tetras like to be in a school of like fish. For the first several days, the platy was active, but now has taken to hiding most of the time. It doesn't look unhealthy and does eat, but is definitely less active. It might just be hiding from the tetra that likes to play high-speed chase.
We did one ~25% water & filter change after the first two weeks. Mostly looking for some perspective on what's happened with our fish thus far, and what to do next. Would it help to get 1 or more additional tetras, or would they all harass the platy? Should we wait to see how the babies get on? I realize we will be overstocked if they all survive. If that happens, what can we do with them? Thanks

 

[dskidmore]

Welcome to Aquarium Advice!

Are you familiar with the Nitrogen Cycle? The food going into the tank turns into fish waste, and that has to get broken down by bacteria before it reaches toxic levels. It is very common to have deaths in a new tank if the bacterial population is too low to support the fish.

A) Don't add any more fish.
B) Do do very frequent water changes.
C) Don't throw out your old filter media untill it gets really gross, or falls apart. Instead, rinse it in declorinated tap water. (I use the old water I just siphoned out during the water change.) If your filter media has more than one part, don't replace both parts at the same time. (Like floss and carbon.)
D) If you don't have them, pick up the following test kits: ammonia, nitrite, and nitrate. We are aiming for 0 ammonia, 0 nitrite, and 5-40 nitrate. If you absolutely can't invest in the kits, use your nose. A strong fishy odor is indicative of nitrogen compounds that need to be removed with a water change.

If you get a hankering for a larger tank, or you have to start over for another reason, look into a fishless cycle. (Good article on the subject here under the saltwater articles. Same principals apply to freshwater.)

 

[dskidmore]

P.S. I don't know how old your kids are, but the test-tube syle test kits are a great way to get kids interested in chemistry. The test strip style would be easier for very small children to use, but is much less interactive and is not as precise. The results of either can be useful for teaching biology.

 

[jlinsey]

Thanks
I had read a bit on the nitrogen cycle, so I understand the basics, but not exactly what to do day-to-day to get it established in our tank. Got the test strips this morning. Nitrate and nitrate were zero, ammonia was 0.5-3. So it seems the ammonia is the problem. Will frequent water changes address this? How frequent and what proportion of the tank volume would you suggest?
Our filter has a replacable one-piece blue mesh over carbon pieces, and a separate biowheel. So are you saying that it's OK to rinse and reuse the blue mesh/carbon part?
We did our first water change by bailing, but today I also got a gravel siphon. I could see when we added the clean water that debris (uneaten food?) was stirred up from the gravel. Does the method have any affect on the establishment of the needed bacteria? If we are overfeeding, how does that come into play?

 

[dskidmore]

If you have live fish in the tank, 50% daily water changes should keep the ammonia levels down to survivable levels. You could also cut way back on the feedings, to a small amount every couple days. Try to get the ammonial level below .25. At that level it will stress the fish without being lethal, but still promote benificial bacteria growth.

If you didn't have fish in the tank, you could just keep testing the water until the ammonia went down.

During the cycle, it is best to not change out the filter pack, because some of your benificial bacteria have colonized there. After cycling, you can still continue to rinse the filter instead of disposing of it. You only need to change the filter pack if you think you need fresh carbon. (Such as after medicating, or if something is producing fumes in the house, or if someone dumps something into the tank they shouldn't.) Once your nitrogen cycle is established, it will be ok to change the filter pack when you think it's necessary.

Gravel washing is a very good thing. The bacteria will cling to the rocks and not be washed away, but you will remove uneaten food and fish waste, which adds to your ammonia problem.

Overfeeding can affect the nitrogen cycle in two ways. If you're feeding the right amount too fast, some of the food will slip by the fish and just get caught in the gravel. This will rot and turn into ammonia. If you're feeding too much at the right pace, the fish will be quite happy with you, but will poop more, which will rot and turn into ammonia. The standard rule is to feed as much as the fish can completely consume in 2 minutes on a daily basis. If you are cycling with fish, you need to cut back on this as necessary to keep ammonia down. The fish can go without food for days at a time, but he can't live through a high ammonia spike.

 

[LKH]

You should get some Amquel, also, to make the ammonia less toxic to your fish during the cycle.

Keep in mind that a fish's stomach is about the size of its eyeball. Try to feed only about that much. With fry, you probably need to feed more often, but in my tanks, four x a week seems to be sufficient - enough to keep the fish full bodied and lively, not so much that I see algae and snails everywhere.

L

 

[dskidmore]

You should get some Amquel, also, to make the ammonia less toxic to your fish during the cycle.

Good point. Prime is also good for this. Don't worry about overdosing on these products, they are mostly harmless even at double dose.

 

[jlinsey]

We did a 35% water change last night with the gravel siphon. That left the baby mollies with < an inch of water in their hanging playpen, so we did not go farther. It took us a few tries to get it working, but then did vacuum up a lot of crud. It's very crowded in there, but if you think it's necessary, we can try to get to 50%. Tested the ammonia this morning and it was slightly less green than yesterday, but I would say in the same range, so will continue with the daily water changes. The platy has been slightly more active, so that's encouraging. When you add the new conditioned water back in, is it necessary to go slow to avoid introducing a lot of bubbles? Some bubbles are getting trapped under the screen on the playpen. Is this bad?
Thanks for your comments regarding feeding...I think the presence of the fry was one reason we were tending toward overfeeding, but now I have a guideline.
Will look for the products you recommended. Also I have Doc Wellfish's aquarium salt which I had read was good for platys and mollies (not sure about the tetra tho). I added some at one point, but that was early on before the original two fish died. I could add it in the correct proportion with these daily water changes if you think it would be useful. The directions don't say anything about stirring it to dissolve...does it just go in as crystals and then dissolve slowly on its own?
Interestingly enough, during the water change we caught the one baby molly that had eluded us, so now have eight in the playpen. It is quite a bit more mature looking than the others (more defined fins and coloration) and about 1/2" long. How big/old do the baby mollies have to be before they start reproducing? I know we have too many already...
Thanks again for your time...I feel we're on the right track and am happy to be learning and taking better care of our fish.

 

[dskidmore]

In a freshwater tank, bubbles are not a problem. There are other reasons to not pour too quickly though. You don't want to pour fast enough to move the gravel around. It is best to get the temperature about the same as the tank when you're filling your bucket, but if you can't, you can avoid temperature shock by only adding a small amount of water every 10 minutes or so. If the temperature match is good, you can pour the water back fairly briskly, just so the poor fishies can keep up with the current, and you don't end up digging a hole in your gravel with water power.

35% is good if it's lowering your ammonia level. If it's not coming down fast enough, you could do more than one 35% water change instead of a 50% water change.

A small amount of salt is good for all fish. Tetras are somewhat sensitive to salt, I wouldn't use the medicinal level on the side of the can with them. When I use salt, I put it in the bucket and swish the bucket around for a few minutes. I pour the water slowly due to temperature reasons, so by the time I'm done, the salt disoves.

Fact of life: if you don't put molly mothers in the pen, she will eat her own children soon after giving birth to them. You don't need to worry about overpopulation if you don't actively promote it. I used to have guppies, it was a similar case. If you want to save all the children, you need another tank to grow out the babies, and a local fish store that will accept trade-ins. Unfortunately many customer trade ins are used as live food, but at least your own kids won't see them being eaten.

I forget how old they have to be to start reproducing. Soon you'll see the boys chase the girls, and a dark spot appear at the rear of the stomach on the girls. (It's called a gravid spot.)

 

[jlinsey]

We did a two 35% water changes lastnight which I guess would roughly be equivalent to a 50% water change. We've made a significant cutback in feedings, too. This morning the ammonia was .25 Tonight I we'll do a 2 x 35% water change again.

 

[dskidmore]

Looking good!

How are the fish behaving?

 

[jlinsey]

The platy is still hiding most of the time but looks fine. It often runs for cover when the tetra comes near although sometimes they "get along". I really hope the platy gets back to being so active like it was the first few days we had it. It is a beautiful fish and really fun to watch. The tetra and the baby mollies never really seemed affected by the high ammonia, but I'm so glad we got it fixed before we lost anymore fish.
We have been feeding flake food & they take a bite and then spit a lot back out...is this normal? Lastnight we fed the babies their crushed up flakes, and just let the bigger fish get what came thru the net.
I read about the fishless cycle with the shrimp from the grocery store....who'd-a-thunk? It definitely seems more humane, but I know the kids would have thought we were nuts had we done that!
This fish stuff is all new to me...but allergies/asthma prevent other types of pets, so we'll just have to learn. I'm still sort of awestruck by being in total control of their environment. I'm looking forward to when we get the tank cycled and can worry about them less and enjoy them more!
I used to fish-sit for a cousin who had a large (~5' long) saltwater tank with coral and all kinds of cool fish, anenomes, shrimp, a horseshoe crab, & a spiny urchin. I didn't have to do much other than feed them, clean the glass and once remove a dead fish. It's sort of mind-boggling to me being involved in a hobby to that level, but then again, he doesn't have kids!

 

[jlinsey]

Hey, we're almost there! We've been able to space out the water changes to 35% every couple of days, and now have had 3 successive days of 0 nitrite and about 10 nitrate. Fish are looking really good and active.

 

[rich311k]

Sounds like you made it. Congrats.

 

[dskidmore]

Yay! Good for you!

 

[Florida8]

Just wanted to pop in and say that the tetra might be a bully to your Platy, depending on which tetra it is... many will harass them to death ... might want to check and see, from your post, sounds like your platy is hiding from the tetra and that won't change more than likely... You might be better off with another Platy or molly in there

Glad to hear the tank is doing better btw

 

[jlinsey]

It is a silver-tipped tetra which I think is not an aggressive type. The chasing is only happening occasionally now, so I think overall the two are getting along OK. It seems surprising that poor water quality would contribute to undesirable behavior, but perhaps it does.

 

[Florida8]

That's great news! Glad there is peace in there

 

[dskidmore]

It seems surprising that poor water quality would contribute to undesirable behavior, but perhaps it does.

You get cranky when you aren't feeling well. Same with fish.