New Tank: How to obtain correct Alk/KH, I, Ca

[kidafius]

my new tank is now nitrate free. BUT! check this out:
Ca 375
KH 12 !!!!!!!!!!!!!!!!!!!!!!!
Alk 4.27
Ph is purple, the darkest on the scale is dark blue at 8.7.

I'm itching to change over the tanks, but I need advice on how to obtain the proper water quality levels and to maintain them, please. I've been using an RO/DI unit for about 2 months now, I'd say 90 % of the water is RO/DI.

 

[kidafius]

Anyone? I've read about every page on saltwater.about.com but they are always talking about how to RAISE Ph and Alk, never how to LOWER it.

 

[steve-s]

You actually do not need to lower the alkalinity, 12 DKH is not a dangerous level. Your chem is out of balance a bit though. You have two choices really. Test a fresh batch of saltwater to ensure the levels there are balanced and do a few 15-20% water changes.

The other would be add some CaCl to bring the calcium up and by default bring down the alk to a balanced level depending on your Mg levels.

>>Here<< Is a good calculator for figuring out the balance.

What do you use to maintain the chem?

Cheers
Steve

 

[kidafius]

I've used nothing for chem, yet. This is after my cylce, and I've just done about a 45% water change to lower my nitrates from 40 to about 5. The new water I use and my tap water coincidentally measure similar to my tank water . Any advice? You say my ALK/KH is fine?

 

[steve-s]

An alkalinity below 15 DKH is fine but relative to the calcium level. Right now, based on the alk level you have, the Ca is too low. The easiest way to balance the two is by raising the calcium. Using the link I provided above, you should be able to find the right target zone. Exact numbers are not necessary, just be in the right range.

If you have been doing large water changes and it has not helped the ionic balance of the water, then the salt mix being used should be questioned and tested. If you have the same numbers as the tank water, then simpley adding a small amounts of liquid CaCl will increase the level of Ca and push down on the alk. Add slowly and test each time to ensure you don't overdose the CaCl and cause precipitation.

I would also suggest reading >>this<< article in order to understand the relationships between these different elements and the many ways available to correct them.

Cheers
Steve