more questions??

[Lynn]

Hi,
I always find this water chemistry very confusing! and yesterday I bought a GH (hagen) kit for testing General hardness and carbonate hardness (which, correct me if I'm wrong ...but thats the same as the alkinity test, right?) Anyways, I tested my well water and the results were
GH 2 drops..then you x it by 20 and that = the answer..which is 40 (ppm)
KH was over 200
then I tested the RO/DI water that I use for the reef tank and it was
GH 12 drops x20 =250ppm
KH was 4 drops =40

My waterparameters for my tank are as follows
Cal=400
Alk (aquarium systems test kit) 3
PH morning 7.9 evening 8.1 (about once a week or so it drops a bit lower and I add some kent PH booster)
Temp 82
Salinity 1.025

In my FO with softies (colts, mushooms etc.) I use the well water. The TDS are high about 670...but the tank looks awesome! and the softies are always fulling expanded and I have very little algae.

My question is ...should I be using the well water for the reef tank? (it also looks good too..mostly LPS and softies) I know we have a tiny bit of iron in the water?? Also how can the well water and basically be totally switched around after RO/DI ...is this what the RO/DI is suppose to do?
Thanks so much

 

[randy holmes-farley]

The TDS are high about 670...

TDS in the salt water tank? I'm not sure what that means. The TDS of salt water is the salinity, and is huge.

The general hardness (GH, calcium plus magnesium mostly) in the tap water is likely fine. Just watch that magnesium doesn't get to high over extended use (you need a magnesium kit for that).

The carbonate hardness (carbonate alkalinity) in the tap water won't hurt anything.

It is the unknown things in the well water that would be more of a concern, mostly heavy metals. Iron is not a concern, but other metals might be (copper, lead, etc).

A properly functioning RO/Di should read near zero on an alkalinity test and on a general hardness test. I can't say why you are getting values other than that either the RO/DO or the kits are not properly functioning. Few people find GH kits useful in operating reef tanks.