Maintaining a 7.0 pH in a freshwater system with a drip

Hello everybody,

First I'll describe my setup. I've got a 180, 150, and 80 all draining back into a 220g sump. One hammerhead is pumping water into all 3 tanks(and 2 UV sterilizers), and I've got a drip of city water coming in at 4gph through a BRS Chloramine Monster. There's an Apex in play with 2 powerbar 8's, lab grade pH probe and lab grade ORP probe. None of it's switch ports are in use yet and there's plenty of open outlets on it's power bars.

Stock is full of very hungry(and very effective at destroying alkalinity) fish. Two ~24" catfish(Achara hybrid and TSN), a ~24" Royal Clown Knife, Oscar, Severum, Rainbow Wolf Fish, Port Cichlid, a ~20" Giant Grourami, and a granulosus.

Just speaking from experience with trying to buffer back when I didn't have the sump or the drip, this stock can easily wipe out 100KH in a matter of hours. I'd usually have to buffer from 6.0 to 6.5, wait a couple hours until it's back to 6, buffer to 6.5 again, wait, buffer again, and then maybe it'd hold 6.5 long enough that I could try to buffer up to 7.0/~100KH the next day so as to not shock the fish. If I did so, it'd be less than a week before it was right back at 6.0/0KH. The process was completely unfeasible so I've only done it when I was expecting to add a new fish.

The tap water here in Portland is usually about 7.0pH and 70-80KH.

I was hoping that the drip, since it drips in the volume of the entire system about every 5 days or so, might improve things. No change whatsoever. Still 6.0/0 after a few weeks. Supplements obviously aren't going to cut it because of the drip, and even if I did take time(I'm guessing this would take months) to load the sump up with just enough crushed coral to keep it around 7 and not spike it up to 8, from what I've read, that would be a temporary effect at best, because crushed coral has a finite lifespan and it's ability to introduce KH to the water decreases as a function of time.

Cost and PITA factor aside, it seems like a calcium reactor is a bad(or outright unworkable) solution for a tank that you want to keep around 7pH instead of 8 like you would for it's intended use in a reef system.

So here I am, I'm out of ideas and I'm hoping that somebody here has more!

knobhill said:

Wow, you have got some pretty high tech stuff going on. So are you adding pure r.o. water into your tanks through the drips system? Your city water is very soft to begin with....

I had a serious pH crash with a tank of mine when I used pure r.o. water on water changes. It doesn't buffer the water since it strips the good and bad solids from the water. So I had to mix 50% city water (treated with Prime) with 50% r.o water.

Now, I have a friends of water whole house chloramine filter with a drip system for 4 tanks using city water. pH is about 7.2, I have never even measured hardness but I know its up there since I am in Los Angeles.

Is the BRS Chloramine monster an r.o unit as well? It doesn't look like it, so I am confused.

Not sure if this is possible, but can you have your pH controller operate a doser/drip with a buffering mixture so you don't have to manually buffer the water?

Click to expand...

I'm not worried about anything from the water except for the chloramines, 1-2ppm ammonia is presently no problem whatsoever because the pH is 6, and it definitely wouldn't be a problem if the pH was 7 because there is literally about a cubic meter of bio balls in the sump. Also, neither ammonia nor nitrates can ever become very concentrated because the drip just dilutes it. I've been measuring all 3 and they are all staying very low even with heavy feeding.

It would certainly be possible to have the Apex use it's pH probe in conjunction with some kind of doser for calcium carbonate or something whenever needed. It would even be possible to program the Apex to check once per interval and do the actual math necessary to know exactly what the dose should be to bring it back to a nominal level. Before I jump off of that cliff, though, I'd like to hear from somebody that has actually done something like that so I know what equipment I need and that it can be trusted, and what the ideal reagent to load it with would be. The idea that some part I found on the internet has to be trusted to accurately dose my tank with something that can easily kill my fish is worrisome. And ideally I wouldn't be needing to create a mixture for it, or at least have to do so very often.

Thanks for the link and info. I'll go ahead and increase it to 12gph and let you all know what happens in a couple/few weeks! That's still only $40/mo of water, sounds like a real bargain to me. I'm definitely not worried about temperature, that hammerhead can keep the whole system at 78-79 degrees all by itself(with ambient temperature controlled at 70, all lids on the sump, and no blower on the hammerhead) before the ~2300w of heaters I have in there(1x300 in the 150, 2x300 in the 180, 1x300 in the 80, 2x300 and a few smaller randoms in the sump) even need to do any work. They're all set between 76 and 77.