pH low and can't seem to figure out why - Page 2

Jpharr · #26 05/08/2006, 01:53 PM

I still need the help of the experts! I have good news. My pH is now very stable. The problem is...it is stable on the low side. It was fluctuating from 7.8 to 8.3. Now it is only fluctuating between 7.8 and 7.95 24/7. I now am using limewater to topoff via a float switch. I am so glad I finally got an automatic topoff system! Anyway, any ideas on why it is still low. Below are the most recent test results taken yesterday. All used salifert.
Ca--495ppm
Alk--3.5mEq
Mg--1425ppm

Notes: My Ca has dropped below 500 for the first time since I started my tank. Mg has finally fallen below 1500, and alk is still somewhat stable. To further complicate matters. I had to switch to IO salt, however, I have put a max of 5 gallons in the tank becasue I daily 1% water changes. Please feel free to give ideas.

Randy Holmes-Farley · #27 05/08/2006, 02:13 PM

Bringing in more fresh air to the room would likely help, if the outdoor aeration test showed a pH rise but the indoor test did not. Did you ever do an indoor aeration test?

The limewater has how much lime in how much fresh water? How much added daily?

Jpharr · #28 05/08/2006, 05:10 PM

1. I did perform the test, and it showed that I had excess CO2
2. I am pulling air from the outside into the aquarium via prizm for about 1 week.
3. I am mixing 1 "heaping" tablespoon/5 gallons of fresh RO water.
4. I would estimate that the AT is pulling about 1-1.5 GPD.

Thanks for your reply!

DrBDC · #29 05/08/2006, 05:33 PM

That's pretty weak kalkwasser. If you increase it to 2 teaspoons per gallon does your ca and alk rise too much? After some more water changes with IO it will have the ca lower which will help the ca number. Maybe try pointing a powerhead at the surface and churn it up in the sump area.

Jpharr · #30 05/08/2006, 06:58 PM

DrBDC, when you say 2 tsp/gallon do you mean rounded or actual tsp. Because there are 3 tsp/1TBS. 2tsp/gallon would equal 10tsp or 3.3TBS. I imagine with the size TBS's I am using I am close to this, but I guess I could double the dose and see what happens. Go to 2 heaping TBS/5 gallons. Don't you love all of this scientific talk!

DrBDC · #31 05/08/2006, 07:56 PM

Shake them just a little and let it be almost flat maybe a little round because at saturation level the excess will just settle out anyway.

bertoni · #32 05/08/2006, 08:16 PM

I would increase the dose more gradually. Monitoring pH and alkalinity will also be important. Overdosing lime can be unpleasant for all involved. If you go to full-strength lime, I'd measure pH after 15 minutes, 30 minutes, 1 hr, etc., as well as checking every day for a few days.

Randy Holmes-Farley · #33 05/09/2006, 06:30 AM

It won't hurt if there is a little excess lime in the limewater. It will just sit on the bottom of the limewater container. If that is not enough pH help, you can also consider increasing the evaporation with fans.

Jpharr · #34 05/09/2006, 06:33 AM

I do continuous monitoring of pH via a pinpoint monitor. I have not had any wide fluctuations. I have my auto top off set pretty tight, so that it will never actually pull that much at one time. My thought behind this, is that it will act more like a drip. I fear that a 1 inch fall before the ATO is triggered could cause a drastic pH swing. Thanks again for the replies!

Jpharr · #35 05/09/2006, 12:40 PM

Randy, are you basically saying to simply increase evaporation to increase top off, which would add more lime, there by increasing pH. This makes since, but I want to make sure I follow the logic. Sharp thinking by the way!

mthedude · #36 05/09/2006, 01:32 PM

are there any other ways to add O2 to the tank?

What do people with very large tanks in newer homes do? I'm assuming a good option would be to install an air exchange sytem to the HVAC in the house to ensure a good supply of fresh air into the home?

Jpharr · #37 05/10/2006, 08:05 AM

Actually, mthedude, the problem is not O2 it is the excess CO2 that drives down pH. The excess CO2 in the home air is no different than the CO2 you "accidently" add via a Ca Reactor for example.

The HVAC idea is a good one, but I don't know how easy that would be to fix. Espesially, if you did not build the house yourself.

I have been opening the window in the "fish" room for the past few nights. Daytime temps are simply too high to raise it during the daytime. That along with the more concentrated lime seem (crossing my finges) to be doing the trick. When I left the house this morning at 0200. The pH was 7.99, which is high for a nightime pH in my tank.

Randy Holmes-Farley · #38 05/10/2006, 01:19 PM

Randy, are you basically saying to simply increase evaporation to increase top off, which would add more lime, there by increasing pH.

Yes.

are there any other ways to add O2 to the tank?

Adding O2 will not help pH. You need to drive out excess CO2. Both can be high at the same time. An air exchanger can help, yes, but is very expensive.

mthedude · #39 05/10/2006, 01:39 PM

I've been thinking of adding an air exchanger to my house, they seem to start at about $400 for a unit that would exchange the air in a 1500-2000 square foot house. Kind of crazy to think we'd actaully spend money on our house to support our reef habit, but people have spent $400 crazier than that I'm sure.

Jpharr · #40 05/10/2006, 04:52 PM

Well, you could look at it like this. $400 for an air exchanger. It would have to be good for your health, because it would get rid of "stale" air. Then with the increased pH of your tank your corals would probably grow faster because they could take up Ca/Alk easier. This would increase fragging rates, and at 20/frag, it would only take 20 frags to pay for it. Sounds to me like you are investing in your tank!

Reefflections · #41 05/10/2006, 09:48 PM

Where have you scene air exchangers starting at 400 bucks?Have any links?I go threw this every year,when have to crank up the AC.

mthedude · #42 05/11/2006, 11:49 AM

Ebay actaully has quite a few air echanger auctions last time I checked. I think I was on DIY or something like that and started checking prices. As always if you go to Lenox or something like that they'll sell you one that's too big for your house and install it for you for a nice chunk on change. It's actually a pretty easy install, just get some 2 inch or larger PVC, plumb one one to fresh air, another end to your furnace/AC air inlet, another line to your air outlet and add a power lead. Pretty easy DIY project if you can get to your HVAC system easily. Luckily I live in a burm home and all my house is 1 level and my HVAC is in my utility/laundry room and could be done very easily. I'll see if I can find a site that has good deals.

mthedude · #43 05/11/2006, 11:54 AM

I know we're not supposed to post ebay links but in the effort to advance the Reef Aquarium hobby and increase the life of our pets, I'll post this one;

http://cgi.ebay.com/Airiva-Heat-Reco...QQcmdZViewItem

johnmsct8astro · #44 05/12/2006, 12:11 AM

i checked my ph ttonight and it is 8.0 nitrate is 0 nitrite is 0 and my ammonia is o i have been trying to keep my ph at 8.4 but iit keeps dropping i have sed buffer but you guys say it not good. So waht can i do to help this out any information will be beneficil. its a 55 gallon aquarium with a sump and two maxi pumps and a proclear skimmer and itsa reef tank. plese reply thnax john

Randy Holmes-Farley · #45 05/12/2006, 06:53 AM

Limewater are aeration with fresh air are the best ways to raise pH. IMO, pH can be anywhere from 8.0 to 8.5, and many folks with nice reef aquaria allow it to drop as low as 7.8, although I'd keep alkalinity unusually high if it drops below 8.0.

This article has more:

Low pH: Causes and Cures
http://reefkeeping.com/issues/2004-09/rhf/index.htm

mthedude · #46 05/12/2006, 08:47 AM

Randy, if PH is 7.8 and alk is on the high side, are there any long term negative effects to the tank? I'm assuming it's just harder to keep Calcium at an acceptable level is ph is low and Alk is ok?

Until I figure out how to blow off the excess CO2 in my tank I'll have to run at 7.8 ph and keep Alk high (which so far has not been a hard thing to do).

Jpharr · #47 05/12/2006, 11:20 AM

It is amazing what simply cracking a window will do. I have been opening the window in the "fish" room at night for about 1 week now. My pH is now consistently above 8.0 at night and reaches 8.25 during the day. I am much happier with this than I was with 7.8-8. Thanks for all of your help everyone.

Randy Holmes-Farley · #48 05/12/2006, 02:51 PM

Randy, if PH is 7.8 and alk is on the high side, are there any long term negative effects to the tank?

The lower the pH, the more stress it is on calcifying corals. That may be partially offset by higher alkalinity. At normal alkalinity, oceanographers are very worried by a drop in pH impacting coral reefs, and they are not talking about it going as low as 7.8.