Ro + Tap Water

[bricko]

Hi folks,

I use remineralised RO water in may fish tanks to lower the PH but am beginning to think it may be unnecessary unless I have very sensitive fish.

Would it be ok to use 50% RO & 50% conditioned tap water without the need to add rebuffering salts to the water? This would also be a cost saving to myself as I would no longer need to purchase remineralising products and cut down on my water consumption.

Let me know what you think, my tap water is about 7.8ph and ideally I have it around 6.5 in my tanks.

Cheers,

Bricko

 

[rabbut]

How about hardness levels, GH and KH? These are the two to look at, as the pH can be anywhere when you have a low KH, but it is the latter that holds your pH steady, so we realy need to know about the hardness to judge whether you are going to have stable water after the mixing Also, why are you using the RO? Just to lower the pH? If so, what fish are you keeping, and what pH do you usualy target?

All the best
Rabbut

 

[bricko]

Hi Rabbut, Sorry for late reply, been flat out at work

Need to get a liquid GH & KH test kit as I only have strips and they are crap!

I have usually targetted 6.2 - 6.5 ph for my wild caught dwarf acaras, but I think they may be ok with a higher PH.

I also have German Blue Rams and glowlight tetras in my other tank which prefer softer PH.

I think I have caused myself some water instability issues in the past just using RO water and getting a bit blasse with reminerallising and not checking after.

I will get the relevant kits and post the results this weekend.

Thanks for your help Rabbut

Bricko

 

[CFC]

The way i see it is that if you have gone to the trouble of providing R/O water for your fish then why would you want to mix it with tapwater and put half the crap you went to all that trouble to remove back in just to save a few pennies a week on remineralising products.

 

[bricko]

CFC, got to agree with your ethos on that really, but this way I would only have to collect 1/2 as much RO per week as I am currently. This would make life easier for me as I am away with work for 2 days at a time in the week and don't always have time to pull off 100+lt of RO per week while I am there. I have thought about setting up a larger water butt outside and constantly leave the RO unit running but this would be quite expensive in water if I were on a meter

What I really want to know is do I need to remineralise if I mixed tap with RO?

Cheers

Mark

 

[CFC]

That all depends on the mineral values of your tapwater, if your water is fairly hard and alkaline then it will perform the same job as adding reclaim chemistry minerals back but it will also add back heavy metals, phosphates, nitrates, hormones and whatever other nasties are lurking in your tapwater. I know that if it were possible to make enough R/O water to fill all my tanks i wouldn't be using any tapwater at all after reading the full print out of the chemical analysis of my local water.

 

[OldMan47]

I use about 50 / 50 RO with tap on one of my tanks. What I have is fairly hard water that measures over 230 ppm TDS. I am trying to breed some fish that like lower pH and soft water so I make the mix. It gives me about 130 TDS in the tank and moves the pH down slightly but not much. When I first started out to reduce the solids and pH of my water I used some RO with the chemicals to reconstitute water but then I thought about it a bit. I do not know what is in the chemical soup they sell to make reconstituted water but I seriously doubt it has all the mineral traces that are found in my tap water. Then I started wondering whether there was naything that my fish needed that had been left out of the chemical soup. That is when I decided that maybe I would be better off not trying to start with pure water and make my own fresh water but just reduce the chemical content with my RO and leave more natural water for the rest.