Water Softener - Is Ro Necessary?

[bish88]

Hi.

I'm new to salt water, having had tropical aquariums before.

I'm in the beginnings of setting up a nano reef. I was advised at my LFS to get an RO system to prepare the water. I live in an area where the water is very hard, and most of the houses round here do not have water softeners.

However, I have a water softener, and I've tested it's hardness which comes out on the test strip as very soft (0 - though I'm sure it must be just slightly above 0 as it hasn't been purified!).

Is it still necessary to put the water through an RO system, or is the softened water likely to be ok?

Thanks!

 

[lljdma06]

It really depends on what you want to keep with regard to corals, inverts, and fish.

L

 

[bish88]

As I'm new to reefing, probably a few soft corals; some mushroom corals, star polyps, xenia corals.

I'm currently struggling to raise the pH above 7.8. It has been cycling for about a week. The SG is 1026. It is a 35l tank with 600l/H flow, made up from a 250l/H filter and 350l/H powerhead. I tried removing the lid... and then turning the powerhead's venturi valve on to agitate the surface further, and still no success.

Could the low pH actually be a result of the water softener? The reason the local water is hard is because the local geology is mostly chalk. However, I've tested the pre-softened and the softened water, and the pre-softened has only a slightly higher pH.

Any ideas?

 

[Donya]

What pH and KH are you getting out of the tap? Test strips are pretty unreliable; is that what you're using for tank pH? If so, take a sample of tap & tank to a LFS that tests with liquid kits to see if you get different values.

 

[Crazy fishes]

It is not pH and hardness why we don't use tap water is all the other impurities in it; nitrate and phosphate being the big two. You actually want HCO3- in the water as it pushes the pH up. You can get buffers that will help to stabilise the pH at > 8 but you need to be patient as it takes time for things to cycle and settle down. If this is a new tank there will be lots of acid being produced by decomposition from the live rock. Once the cycle is complete and you have fish living happily in the tank you know that an equilibrium reached and then start looking at the pH etc. I would measure ammonia, nitrite and nitrate and once ammonia and nitrite are zero you can do a water change and add fish. At this point recheck the pH.
 
Kindest regards

 

[DrRob]

Worth noting with water softeners is how they work. The most effective ones work by exchanging the calcium ions in the water for sodium ions, making the calcium chloride into sodium chloride. Not generally recommended to drink regularly in properly hard water areas as the sodium content gets a bit high. For freshwater tanks this can be a problem as it adds a fair amount of salt to the tanks. As said above it also does nothing for the other rubbish that is found in tap water.

 

[Donya]

It is not pH and hardness why we don't use tap water is all the other impurities in it; nitrate and phosphate being the big two

 
 
Hardness is certainly the reason I don't use it. KH of just of 2-4dKH is enough to really mess up some salt mixes and the pH and KH in some marines tank long-term, even with nitrate, phosphate, and copper being undetectable.