High kh@15 but only 7.7PH what can I do?

[Deron Ng]

Hi I currently have this problem could it be running chaeto 24/7?

[brent]

It's doubtful that it has anything to do with chaeto. If fact, lighting chaeto 24x7 should raise you ph. You need to provide a lot more detail. Tank size? Are you dosing? If so, what are you adding and how? What test kits are using? Have you verified the numbers using another test kit? Are you running a CA reactor? What type of flow do you have? Etc. If your tank chemistry is messed up and you don't understand why, the safest thing to do is stop dosing and do water changes.

[Deron Ng]

No dosing.. Weekly 10 to 20% water change.. Ph at 7.7 Kh at 15 Ca at 500 No3 and phos at min.. Less then 1ppm Using api testkit and no ca reactor.. Phos test using salifet

[brent]

Those numbers seem almost impossible without dosing. I've had bad luck with API test kits. Salifert or Red Sea are much better.

What's your salinity? What salt mix are you using?

In any case, try taking a cup of your tank water and add an airstone to it bubbling it very vigorously for 30 minutes. If the pH goes up, then you probably have insufficient flow / aeration in your tank which is resulting an excess build up of CO2 and depressing your pH. That would be my guess assuming that the tests are giving you the correct readings.

[Deron Ng]

Instant ocean reef crystals.. Just water change no dosing.. Maybe is api not accurate.. But my brains not doing very well.. SG at 1.025

[Deron Ng]

Photosynthesis take in co2 and release O2 right? So 24/7 chaeto provide lots of O2 am I right.. Btw they are growing like crazy..

[Evolutionz]

chaeto should never be running at 24/7. best is reverse cycle of your current lighting. kH 15 is way too high. try to find a lower kH salt mix and slowly lower it to 8-9.

[Deron Ng]

How to lower? This brand of salt I heard is quite good recommended by madpetz.. Maybe my water change too frequent or too much ?

[Deron Ng]

Am I am not wrong to say 24/7 photosynthesis will increase the ph not lowering it?

[brent]

Yes, 24/7 lighting on the chaeto raises pH due to the photosynthesis. Some people like to reverse cycle their fuge lights and main tank lights to moderate pH swings between day and night. Some people will run 24/7 to maximize nutrient export and avoid some macro algae such as Caulerpa from going sexual.

In any case, chaeto would not be causing any of the problems you're mentioning.

Try that trick with aerating the water. That should give you an idea if you are having problems with low flow.

Also, sometimes salt separates in transport which can cause some problems since the bucket is chemically inbalanced. You need to mix the entire salt bucket before you use it.

When I started out, I also used API. Eventually I had so many problems with the accuracy that I threw them out and bought Salifert. Get some decent test kits.

[yellowtang]

IMO, nothing to do with the cheato, off your salt brand.

Check your mg.

Ok, check your Kh test kit.

Check the Kh of your freshly prepared salt water. The Kh shd be ad per specs.

YT.

[Deron Ng]

Ok.. Will buy some new test kits and update later

[brent]

Good luck.

If it turns out that it isn't a problem with the test kits, here's a couple of good articles on correcting chemistry problems in saltwater tanks.

This guy is the master of reef chemistry:

http://www.advancedaquarist.com/2002/11/chemistry

http://www.advancedaquarist.com/2002/6/chemistry

[brent]

One more. This is the most relevant:

http://reefkeeping.com/issues/2004-09/rhf/index.htm

[Deron Ng]

Hi just some updates.. Been changing all test kits to salifet..

Dkh at 9.9

Cal at 450

Ph still at 7.8 to7.9

Need help here?? Try at add aeration into sump see what happens. Cheato running at 24hr..

[CFOh]

7.8 to 7.9 at day or night? Check diff photo-period & check from main tank.. if night and young system, shld be marginal but not really bad yet. Day shld be >8 at least.. Drip kalk during night may helps..

do you have any carbon media or any acidic filter? Try remove them for the moment. Try remove any died to avoid this? Also, depend how mature is the system.. Normally young system tends to tendency of PH swing.. As long as not over populate yr tank shld be fine.

Do not stir your sump. May have adverse effects...

Cheers and Happy Reefing..

[Deron Ng]

Ph low at night.. May go up to 8.1 in the day.. Currently adding air pump in cheato sump.. Now dkh and cal alrdy at good levels shld I still drip kal at night?

[CFOh]

Ph low at night.. May go up to 8.1 in the day.. Currently adding air pump in cheato sump.. Now dkh and cal alrdy at good levels shld I still drip kal at night?

8.1 oklah. your tank is ok. new tank syndrome... you can stop the air pump, I dun see it helps your cheato.. Just ensure your flow exchange at least 10x shld be good enough. No harm to drip kalk as long as not overdose.. Will helps to grow your Coraline too.. Cheers and Happy Reefing..

[Deron Ng]

Flow exchange as in what? I am using a 2800l/h for my 4x2x1.5.. With an wp40 inside..

The range of 7.8 to 8.1 is ok meh? Because I see my lps like not very happy leh.. Not fully opened up..

[CFOh]

Flow exchange as in what? I am using a 2800l/h for my 4x2x1.5.. With an wp40 inside..

The range of 7.8 to 8.1 is ok meh? Because I see my lps like not very happy leh.. Not fully opened up..

If due to PH, The impact is more drastic. As mention it is marginal but not really bad. you need to check your placement, flow direction & water temperature also other parameters as well. eg, Brain do not like direct flow...

flow exchange, for example your tank Volume 340L (u may need to add yr sump volume) & your pump 2800l/h is about 8x your main tank valume. Shld be just enough depend how perfect your want.

[CFOh]

Flow exchange as in what? I am using a 2800l/h for my 4x2x1.5.. With an wp40 inside..

The range of 7.8 to 8.1 is ok meh? Because I see my lps like not very happy leh.. Not fully opened up..

Fyi,

http://reefkeeping.com/issues/2004-05/rhf/

Cheers & Happy Reefing..

[Deron Ng]

Maybe new tank.. I give it some time see how! Thanks anyways