Half My Tank Has Been Wiped Out

[tyyrlym]

Simple, RO has a pH of 7.0. If your tank has a significantly different pH and you add in RO water it can lead to a massive pH shift. A huge pH swing can kill a fish quicker than ammonia could ever hope to.

If your pH is close to 7.0 to begin with that's not likely to happen. If you've been using RO from day one no problem.

This is not good advice.

My post was in response to someone who was using a mixture of RO and tap water and as an explanation as to how the RO water could have killed the fish. Taken in context there's nothing wrong with what I said. If you want to take it as a blanket statement that RO water has no problems at all ever then yes its not good advice.

 

[orange shark]

i don't understand why RO water would kill most of your fish, have you added anything else to it?

 

[k.o.d]

Fair enough, It was not meant as an attack but RO cannot sustain life, and I do agree that a stable pH is more important than people give credit for.
Reverse Osmosis water must be cut with, in the case of freshwater, either a buffering agent such as Kent RO rite or with a percentage of treated tap water or in the case of marines, used with the synthetic salt when initially adding the water.

Neat RO can be added to a marine tank when topping up the levels due to evaporation

Steve

i don't understand why RO water would kill most of your fish, have you added anything else to it?

It is not what you have added to the water, it is what you have taken away

When you have removed the water for water change, you have taken away water with buffering potential and added water with no buffering potential whatsoever, so ( and this is hypothetical ) it has been a while since the last water change and the buffering capacity is close to exhaustion, you have now decreased it even further, so this allows a pH crash to happen.

have seen it often and when it happens it happens quite quickly.

Steve

 

[orange shark]

oh ok...good answer!

 

[Miss Wiggle]

in terms of 'instant death' the most likely cause from the RO is a sudden change in parameters, massive pH swing or such like

in terms of long term use pure RO shouldn't be used because it contains no minerals, fish absorb minerals from the water by osmosis, put them in water with no minerals long term and they will suffer health problems because of it. However short term this will not harm fish significantly.

 

[Se7enUK]

Well I have spoken to Lincoln Aquatics and they are noit interested in doing anything, in fact they even suggested this could be caused by local crop spraying and me leaving the windows open!!!!
I will not be looking to visit the shop again and they are still saying its OK to add RO water to Tropical Fish tanks.

As stated above the deaths seem to be a result in the RO water causing a massive pH swing, cheers Lincoln Aquatics!!!!!!!!!!

http/www.aqua-topia.co.uk/ is their website and recommend people stay clear!!!!!!!!!!!!!!!!

I have rang and visited other LFS and they have all said not to use RO water in tropical, especially with our normal pH being high. They have also advised that as in my case with a newly established tank that it causes havoc due to the lack of silt build up etc and can crash the pH easily......

Anyway you live and learn!!!