multiple Fresh water fish dead

[gjuarez]

did you aerate your water?

[Polkster13]

Well Plecos are vegetarian. They will eat wood matter as well. It is good thing to keep some wood in the tank for them to munch on and they will usually be found napping there as well. To kill a pleco, it either starved to death or there was a bad chemical in the water that it absorbed. Because of the osmosis effects of fresh water, freshwater fish get water logged and have to pee to reduce the excess water in their system. They only "drink" water when they are eating. That is why freshwater fish can survive in very unclean water. However they do absorb a lot of things through their skins like heavy metals.

That is why I was concerned about the carbon filtration on your system. If your RO unit only has one carbon filter and you have chloramines in your water system that may not be enough. You might want to think about adding another carbon canister to your system. Also, how often do you change the carbon in your biowheel filter? Depending on the size of the tank, you may need to replace this a little more often.

Loaches are also pretty hearty. I am suspecting that the pleco died first, probably from starvation and polluted the tank. The loaches probably scavenged the pleco. If the tank were undersized for the amount of inhabitants (plecos should not be kept in ANYTHING smaller than a 50 gallon aquarium), the tank would have gone south on you very quickly creating a domino effect. If you need something to eat algae in your aquarium then I would suggest you look at otoclincus catfish. They stay small (1 to 1.5 inches) and like to be kept in groups of 4 or more.

[Polkster13]

Pleco is a generic term for many types of fish that resemble the plecostomus. What you commonly find in the fish stores is Liposarcus multuradiatus which will grow to about 2 feet long. Some "plecos" are omnivores and some are true carnivores. What most fish stores sell are herbivores to people so they can "control" their algae in their tanks. What they don't understand is that you have to feed these fish suppliments as the algae in the tank will not keep them alive for long. They do NOT eat other fish waste and they should not be considered "cleaner" fish. They need huge amounts of food fiber to survive, hence putting in the wood for them to munch on. They do make an attractive addition but they are not secondary fish. You have to meet their dietary needs or they will starve to death.

[bigdscobra]

I dont think he starved to death... He was always eating it must have been something with that water change.. I did another change with no RO water and havent had a problem since.. The pelco was only 2in long had him for over a year so he was still ok in that tank. I think it might of been that i never used RO water on the freshwater tank, i got the unit for my saltwater tanks and thats what it has been used for with no problems... I have had this tank for years and never had a problem like this with 4 fish dieing.. I got a new pelco today, the remaing fish seem to be doing ok ... The RODI unit has 3 carbon filters on it.. I have never used dechlorfire with it since i got it because i thought that it took all that out. The food fiber for the tank comes from this large plant in the middle it takes up alot of the tank. the leaves that fall off the pelco usually eats... I dont know what plant it is just a potted one from petsmart which has been in the tank for over a year..

Thanks for everybodys help!!!!!!!!!!!!! It was just werid never had that problem before.. I have had that tank since we moved here over 16y ago so this was the first time anything like that has happened..

[Polkster13]

Oh. I think I may know what happened. If I am reading this correctly, you have always used tap water before for your freshwater tank, Then the last water change you used RO/DI water. Is that correct?

If so, then it was a pH shift that probably killed the fish. The tap water around here is around pH of 8 and the RO/DI water is around pH of 7. if you did a 50% watre change that would have been enough to burn the fishes gills and that would also explain their behaviour prior to death. If you have a pH test kit, test the pH of your tap water, your tank water and your RO/DI water. I think you may find your answers there.

Let us know what you find.

[TexasTodd]

Dan, if you have been using SA tap water on the tank thus far..........and I believe you have since I know you haven't had a ro/di unit long, and then did a fresh water change with RO/DI ...........

YOU COMPLETELY F'D THE PH MY FRIEND. RO/DI water can't even be run through copper pipes because it will eat them. Not that we'd run anything for the fish tank through copper, just let's you know what it's like.

When we add Kalk or synthetic sea salt to the ro/di it buffers these problems out.

Just use regular SA tapwater with delcor additive stuff on your freshwater tanks. Not a fun lesson.

Sorry about the loss.

TT

[LoneStar]

yeah thats what i heard too

[bigdscobra]

Dam thanks for the help Todd.. Dont think I will be adding anymore RODI water to that tank.... Got some new cool looking tetras though, have a orange stripe..

[bigdscobra]

yeah thats what i heard too

Thats cause you were there when Todd told me that :roll

[LoneStar]

no, thats what i heard on the internet before todd told us