Kh is WAY too high, help!!

Amanda and I did a water test this morning and we have come to a conclusion that we have no idea why the KH is increaseing. the only possible solutions i can think of is that we have texas holy rock in our tank, along with one rock i made myself. Any sugestions?

Not enough live rock?
Not enough air bubbles?
Bad filtration? (Rena XP2 Canister with bio balls, carbon, phos remover)
Bad water? (we use RO water from a local water store)

Water conditions (water change last week) 100 gallons:
pH: 7.8 (we've been having trouble keeping this up for a while, even with API proper pH 8.2)
Ammonia: .5
Nitrite: 0
Nitrate: 0
Calcium: 440
Phos: 2 (this has recently been elevated)
Temp: 79
KH: 25 drops (usually we are at 13)

 

First things first. I would doublecheck both your pH and your KH readings with a friends test kit just to make sure you don't have bad reagents.

It sounds like you're probably getting hit with a 1 -2 punch here. You're trying to increase your pH so you're dosing Sodium Carbonate. Well, Sodium Carbonate increases your Carbonate Hardness (KH). Additionally, because you're pH is low, you're rock is dissolving further increasing your KH. (The dissolving of the rock is probably releasing adsorbed phosphates).

I would solve your pH problems in other ways. Chemistry and the Aquarium

You can drop your KH by dosing enough Calcium Chloride to trigger a carbonate snowstorm. However, if you're not experienced with reef tank chemistry, this could be a little challenging.

 

How long did you let the homemade rock hydrolyze or "cure" before you put it in your tank?

 

I use a 29 gallon tank with a filter that moves the water. I use old water from the tank from water changes. It had been sitting in the 29 gallon for over 5 weeks, maybe 6. before i put it in. I placed it in bowl by itself for a day and tested that water initially and after the day had past, there were no changes to the water it was sitting in

 

Thanks for the link curt, that does make sense, ill get a friend to come test later and read the link. We are new to this but with enough research nothing is impossible

-Dan

 

What do you have for flow? I don't see any power heads etc. Your low pH could be a lack of O2 due to poor circulation. The low pH can cause your rock and sand to disolve as inwall stated and raise your Kh.

Jack

 

We have a hydor koralia 4 and 3, one on either end of the tank, the three is always on and the four kicks on with the lights, 8:30 to 11:00am and 4:30 to 8:00pm.

A friend came over and test and came up with the same results, we decided to build a sump with an extra 29 gallon tank i have this weekend, looks like we will be buying also a skimmer so if anyone has suggestions for designs that would be appreciated, we are also looking at the Octo 2000.

 

well im not sure what helped but it was probably the sum/skimmer/fuge/purple up that cause us to go down to 13 instead of 25 =)

 

To drop my KH when it was high.. I had to take kalkwasser powder and water and mix together.. slowly pour this solution into tank every few hours.. test KH next day.. and repeat.. may take a couple days, your tank will get very cloudy.. once KH is in aceptable range.. stop.. also your PH buffer may also raise your KH, so check the labels to see if thats the problem. also you may want to check your Mg levels.. I believe higher Mg levels need higher KH levels to coincide.