Will my tapwater B safe 4 reef?

[gobyinpeace]

I am new to SW and would like to eventually begin reef building. I am hoping to use my water for my 20G. tank. My water comes from a well that is high in phosphates, calcium and iron (South Florida). The well water is treated with a large aerator and there is an RO filter in the kitchen. The RO filter drops the PH dramatically. I was thinking of placing the RO filtered water in 5 gallon buckets with large ancient fossilized coral rock and crushed shells, to bring the PH up to 8.0-8.2. I will be using Instant Ocean and have a couple of questions.
Should adding the salt mix be done when I place the RO water in the bucket with the rocks and shells or should I add it after the PH has risen to 8.0-8.2?
Does an RO filter do a good job at removing heavy metals and phosphates?
And most of all do you think this water will be clean enough for a reef tank?
I prefer to do frequent water changes in all my FW tanks and would like to do the same with my SW tanks.

 

[broomer5]

Hi GobyInPeace
If your RO unit is in good condition and working order - you may be able to use your well water after running it through the RO.
Best thing to do is to mix up a gallon or two of the saltmix & RO water ..... then run a series of water tests on it.
Make sure you mix the saltwater in the five gallon bucket, and place a powerhead in the it .. let it run overnight this way.
Next day ...
Test for
salinity ( get it to 35ppt full strength )
pH - should be around 8.0 to 8.2
ammonia - may find a trace but should be zero
nitrite should be zero
nitrate - should be zero
phosphate - may find a trace but should be low
calcium - should be around 370 ppm
alkalinity - should be around 2.5 meq/L ( 7.00 dKH )
This will give you a pretty good benchmark, and will let you know some of the parameters.
You can also run a series of tests on the RO water itself.
Let the RO water aerate in a plain plastic bucket for several hours as well ... before testing.
Test for
pH ( should be somewhere between 6.8 and 7.2 )
calcium - should be low
alkalinity - should be low
phosphate - should be low
If possible .. run same tests on your well water BEFORE it runs through the RO unit.
Test for
pH - should be higher
calcium - should be higher
alkalinity - should be higher
Write all your test results down.
This will give you before RO, after RO and mixed saltwater test results. The more you test .. the more you'll know.
Then ..... you can make a good decision whether or not to use this freshwater for your reef tank.
There is no reason to soak the fossilized rock in RO water.
Neither for saltmixes or for evaporated top off water.
Mixing Instant Ocean in freshwater of high pH can lead to some unusual results - most likely too high calcium or alkalinity.
Instant Ocean synthetic saltmix is designed to mix with freshwater ...... pure freshwater.

 

[slick]

Great reply Broomer.
As far as your water goes. You want your waters PH to be about 7 like said above. This means your water is neautral. When you add your salt mix it will move it to around 8.3 +or-. I agree with testing your water at various stages to make the best decision.

 

[gobyinpeace]

Thanks Broomer and Slick. It shows how green I am with SW. I had no idea about the Instant Ocean effecting the PH to that degree. I did test the PH levels of the RO water vs the wellwater and the RO is right around 7. I will make the testing Broomer suggested and take it from there.
I also found my blacklights (I am a kinetic light sculptor) to be a good tool for visually checking phosphate levels. Water with high levels of phosphates glows somewhat and appears very cloudy. Water without phosphates does not glow and is clear.