Kh Ph Help

Just finished up setting up my tank and almost ready to start a fishless cycle. I've got a couple questions. My water is super soft like 2kh. I added some crushed coral to the filter last week but still haven't seen my kh go up any. pH is around 7.4. Will I be okay to start my cycle with those pramaters or will it still out? Also will guppies be okay in that condition of water. I know they like hard water but don't k ow what other to do to bring kh up without pH getting super high. Any help is appreciated

 

Your cycle will be fine with that pH and hardness. Guppies should be fine too. Note that it does take some time for the crushed coral to raise the KH. Also, you may need to add a bit more.

 

Ok awesome. I'll get it started soon. I added over a pound to the filter in a media bag. It's all the room I had left on top of biomax rings in fluval 406. If needed I can drop another bag in the tank. I'll just give it some time and see. What's a good balpark estimate of how long it takes to see an increase?

 

Your pH and KH is fine.

If, during fishless cycling, your pH and/or KH crashes, a quick fix is to simply use baking soda. Use 1 teaspoon per 10 gallons of water.

It's important to maintain some degree of carbonates while cycling as nitrifying bacteria utilise CO3 as a carbon source for metabolism and reproduction.

 

That's what I was thinking. I've saw a lot of people's pH drop and the cycle stalls out. I want to avoid that if at all possible

 

The precise relationship between pH and nitrifying bacteria isn't very clear from the literature.

This is my post from another thread:

"Fumasoli, Morgenroth and Udert (2015) indicate that while ammonia- and nitrite-oxidising bacteria are widely observed to have decreasing metabolism in acidic environments, they report that the reasons for this phenomenon are not well understood.

Suzuki, Dular and Kwok (1974) reported that the protonation of ammonia into ammonium ions at low pH is the primary reason for reduced activity, as ammonium is unable to diffuse across cellular membranes for metabolism by ammonia-oxidising bacteria.

However, Wett and Rauch (2003) finds that the low concentration of ammonia at low pH is overstated, and that it is more likely the formation of H2CO3 in acidic media and its volatisation as CO2 reduces the availability of total inorganic carbon necessary for ammonia oxidation. In addition, Gieseke, Tarre, Green and de Beer (2006) suggest that ammonia oxidising bacteria possess ammonium transporters that nevertheless enables the metabolisation of ammonium ions even in acidic environments."

I tend to follow Wett and Rauch's (2003) position that low pH leads to a lack of inorganic carbon: to remedy this, you can simply dose sodium bicarbonate (or any other carbonate salt) as it'll both replenish carbonates and raise pH.