Kh

Originally Posted by ThErMuS

I have a marine tank for about a year plus... Without any corals... just some tangs and angels.. i have a problem... my KH is always so high... anyway to lower it??????

What is your PH level? It is interesting..did you dose anything recently?

Originally Posted by angmoh

so meaning that the low kh is due to low CA as well ? so i hv to dose KW ? hehe , cos i never add any additivies to my reef tank. btw most corals i'm keeping is shrooms and buttons

Low KH , High calcium. High KH , low calcium . Check ur MG level . All this had make me gone crazy liao.

Originally Posted by ThErMuS

if tt the case...corals wont open up also?

U just say your system have fish only! U haven't tell us wat have u dose or what's your test reading? if your dkh is really high then i assume that u have high pH too. Corals will still open even with high dkh unless it's way very high.
Test ur dkh and calcium then post it here.

Originally Posted by monsterz1975

Low KH , High calcium. High KH , low calcium . Check ur MG level . All this had make me gone crazy liao.

I'm going mad trying to get everything in correct order too.. I hate chemistry..

Originally Posted by angmoh

so meaning that the low kh is due to low CA as well ? so i hv to dose KW ? hehe , cos i never add any additivies to my reef tank. btw most corals i'm keeping is shrooms and buttons

Like what Bro Monster says, KH and Ca are always opposite. Dosing one will decrease the other. However in my tank, I do find that KH drops much faster the Ca. I only dose Ca once every 2 months but I have to dose KH twice a week to maintain my KH at 10.

Dosing KW will not help. KW is meant to maintain the KH and Ca at a current level. It will not increase either one of them.

Originally Posted by angmoh

sorry to hijiack , but my kh is about 6-7, is it considered low ?

and from that, can i know my CA level without the CA test kit ?

Hi angmoh,
If u have done any regular water changes & without dosing any Ca before, then I guess your Ca would be around 200-250ppm, which is on the low side & just enough to sustain soft corals, seriously could not keep any LPS in long term. A good start of carbonate hardness would be 8-10 dkh. Your reading of 6-7 dkk which is very low, so I suspect u might not change any water or not changing very often. Out tap water has a reading of more than 8dkh with those salt mixes, u can test it yourself to verify that. Lastly, if u want long term success with corals you should get a good Ca test kit e.g. salifert and dose Ca with testing. Kalkawasser which is a good Ca supplement, it supports dkh also.

Originally Posted by angmoh

so meaning that the low kh is due to low CA as well ? so i hv to dose KW ? hehe , cos i never add any additivies to my reef tank. btw most corals i'm keeping is shrooms and buttons

Low Ca has nothing to do with low kh. In my previous post I’ve said that they existed in Hi-Lo relationship. That’s to say that if u have a tub of salt water, it can only contain a fixed amount of Calcium and carbonate hardness. More calcium will make less room for KH, & versus versa. e.g. if u have 450ppm then very likely you will have 8-10 dkh, or 250 ppm, 14 dkh. Most aquarist maintain high calcium and low kh because most corals can be grown in this kind of setting. U can’t push both Ca & Kh to the higher end though, u might risk your system to crash if they fall out of solution.

Assuming that:
U want to make a cup of coffee, the coffee powder is calcium & pure sugar is KH. The cup is your fish tank. U have a fixed rule here: 1)If u want a cup of strong coffee then more coffee powder is added, with enough sugar to make it taste good. U make a cup of good coffee. 2)If u love sweet and dislike strong coffee, then u can add more sugar & less coffee powder. In the end u make 2 cups of good coffee. Now image the 1st scenario, more coffee powder & less sugar added, u think it’s not sweet enough so u add sugar. At this point the coffee is almost reaching the rim of the cup. If u continue to add more sugar, what happen then? Of course the cup overflow, coffee spilled everywhere! So always remember that u can have so much quantities of Ca & KH, anything exceeding natural level can be disastrous to your system.

Originally Posted by dradttg

Like what Bro Monster says, KH and Ca are always opposite. Dosing one will decrease the other. However in my tank, I do find that KH drops much faster the Ca. I only dose Ca once every 2 months but I have to dose KH twice a week to maintain my KH at 10.

Dosing KW will not help. KW is meant to maintain the KH and Ca at a current level. It will not increase either one of them.

Because Ca has a larger pool of quantities than carbonate hardness, if u do dose 2 parts suppliment KH will dip in time. So minor correction need to be done very often to adjust DKH to correct the imbalance.

Originally Posted by subxero

I'm going mad trying to get everything in correct order too.. I hate chemistry..

hahaha... that's is fun about chemistry. my mg always at the low side till i replace 1/3 of my tank vol mix salt water and now my mg is on the high side i guess coralife salt have a high mg

Originally Posted by monsterz1975

Low KH , High calcium. High KH , low calcium . Check ur MG level . All this had make me gone crazy liao.

Check your MG and tell us your PH?

Regards