View Full Version : Ph and refugiums

10/04/2017, 12:20 PM
Ok so I have been having low ph problems for years. Yes ph probes calibrated, New ph probes new calibration solution. My ph drops as low as 7.6 high is only 7.9.

Corals all do good but I know if I could get my ph up it would increase growth of my sps.
So to my question.

I have added 2 separate 40 breeder refugiums both lit with the Kessil h380. I was wondering on your thoughts

1. running both fuges reverse lighting to my display.

2. just running one fuge 12 hours and the other fuge on for 12hours when first fuge is lights out.

3. Running fuge like option 2 but for 16 hours so one is always on but this way both refuges would be running at the same time for some of the display lights out?

Thx for info


10/04/2017, 03:43 PM
I tend to be cautious, so I would light one refugium on reverse lighting, and see how that goes. If that's not enough, I'd light the other. That's probably excessively cautious, but those pH levels are safe, so I'd prefer not to rock the boat very much.

Have you checked the aeration capacity? It's very rare to have an aeration problem, but checking quickly to make sure that there's no surface film, and looking at the skimmer (if present) to make sure that it's producing a good stream of very fine bubbles tends should only take a few minutes. I kept a good rippling motion on the water surface of my tanks to make sure that aeration was okay.

10/04/2017, 04:08 PM
I already lit one refuge it didn't do much at all so I got a light for the second fuge today. It's high co2 levels in the house causing the problem. I know that I bought a co2 monitor for the house air it is high. I live in Florida with hot summers and a new house so little air exchange with outside air. Should get a little better in the winter I can open the house once in a while.

Why so cautious with a refuge? I don't see a negative to having more refuge? Why the caution?

10/04/2017, 05:47 PM
Well, there's really no dramatic need for the caution, most likely, but I'd hate to be be wrong and kill corals. A very large and effective refugium system might be able to cause problems by outcompeting some corals for dissolved nutrients, for example.

If the carbon dioxide is very high, you might be stuck, but the next step to consider would be to try a carbon dioxide scrubber. You could make one for a few dollars from a soda bottle, if it comes to that.

10/04/2017, 06:15 PM
Thx for info but I already tried

1. running airline for skimmer outside
2. Double chamber co2 scrubber
3. Saturated limewater

All with very little results

10/04/2017, 07:33 PM
Well, I'm not that surprised. A fair numbers of tanks seem to have this sort of problem with pH. I'm not sure what else you could do.

10/04/2017, 09:00 PM
Are you using a calcium reactor to supplement?

I use two part, but recently added a CO2 scrubber and the polyp extension is now ridiculous and I'm finally seeming noticeable growth.

Good luck!

10/05/2017, 09:11 AM
Hi Roger,

I had the same issue, also the root of my problem is CO2.

I also tried many things, what worked better for me is adding Kalkwasser.

I started with 1 tbs for every gallon in my top off reservoir. And raised to 1.5 tbs this week, finally my Ph is above 8 for the first time since the heat started (summer). Had to switch the salt i was using to ensure maintaining an acceptable Alk; was using Redsea Coral Pro (12 Alk), now I'm using regular RedSea (8 Alk)

First, I tried the CO2 scrubber through direct line ti protein skimmer air intake. It raised it from 7.6 to 7.8 but only lasted 2 days, the media consumed really fast.

Then I tried running a line to a jar with water to make media last longer, same figures but now CO2 lasting 5 days.

In parallel I built an air line from outside. A mayor project, as it has to go though the wall and is 30 ft long. Its a 2 inch wide PVC running from outside to the sump and also to the inline of the CO2 scrubber. I even placed an in-line fan connected to Apex, so the fan starts pumping fresh air when Ph is below 7.8. All of this did not make any difference.

And also stated a refugium, first with Kessil 180, did not work at all. And then switched to a H380. I started running it 16 hours reverse schedule, and it did increase the Ph but just 0.5 pts. But also started to face hair algae grow in the sump and had to spend hours cleaning it. I just lowered to 12 hours with similar Ph results and no mayor algae issues yet.

Just as a side note. My excess CO2 problems started with the heat wave. I used to have 8.2 ph in March/April.

Will continue to monitor, and evaluate if CO2 scrubber is needed in the upcoming months.

Sent from my SM-G955U using Tapatalk

10/05/2017, 11:14 AM
Thx for info but I already tried

1. running airline for skimmer outside
2. Double chamber co2 scrubber
3. Saturated limewater

All with very little results

Hmm, you must have really high CO2 in your house then. Each of those fixes should have moved your PH a little higher. Especially the limewater.

What I found worked for me and moved my PH up by about 0.2 units, was a whole house HRV. As you are in Florida, an ERV would be more appropriate. If your tank is in wall and inside an enclosed space (like in a fishroom), you could try a smaller ERV intended for single rooms. Normalizing he CO2 level will almost certainly correct your suppressed PH.


10/05/2017, 05:40 PM
I use an ERV and yes it helps. My house stays around 850ppm co2. During cooking(gas) co2 shoots up to 1500-1800 and stays there for some time unless vented. I think even with running the skimmer outside, the tanks surface exchange/sump is enough to override the fresh air skimmer when the C02 levels are high. My tank was consistently
at 7.6 to 7.7 before ERV and fresh air to skimmer. Now I get 7.78 to 8.0 depending on amount of fresh air in house. ERV only 7.9. Windows open all day 8.0

03/10/2018, 08:58 AM
WOuld an algae scrubber work better than a small refugium?

03/10/2018, 08:59 AM
I have a 37-gallon cube and a 25-gallon sump with a 4-gallon refugium section, but my pH is still 8.1 and I know higher can be better, would running an algae scrubber help of maybe a CO2 scrubber?

03/10/2018, 01:45 PM
The approach that encourages the most photosynthesis would work best for improving the pH, to a first approximation. I think that "algae scrubber" is used to describe various setups. The old dump bucket algae scrubber might be more effective, although noisy.

8.1 is very good for pH for a tank in a house. I'd leave well enough alone, but you can make a carbon dioxide scrubber for a few dollars and get an air pump to see how well it might work. I think that Kalk would make a decent first stab at media, although other chemicals should be better.