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View Full Version : RO/DI pH Problems.. some help please



adikt
11-07-2006, 02:02 AM
Okay so about 2 weeks ago I purchased a RO/DI unit off ebay (filters direct). Everythings installed perfectly fine and I drained atleast 15 gallons of water before use. (yes even made sure the water I'm using isn't the waste line).

Well I started to top off with the new RODI water and about 2-3 days of topping off (almost a gallon a day) I noticed my corals closing up.. and my candy canes really pulling into it's skeleton.

So I checked all my params.. normal as usual.. EXCEPT my pH in my tank was @ 7.6

Do you guys add any pH buffers to your RODI water for top offs and/or water change salt water?

I've been adding Red Sea Marine SUCCESS Buff (I know cheap stuff but it's what I had laying around) about 3-6 mL a day for the last 3 days slowling increasing my pH back to 8.1~.3

What do you guys advise?

*i just orderd a few pounds of kalkwasser* I was told to add this to my RODI water before top offs from my LFS

jsmkmavity
11-07-2006, 02:26 AM
it is common for tap water filtered with rodi to have a low ph. if mixed with salt a day or 2 in advance and well aerated and still has low ph then add enough buffer to correct. usually proper aeration will get you close if your using a high quality salt mix.

Scooterman
11-07-2006, 07:50 AM
I'll post this link you should read, I think it will help.

http://www.reeffrontiers.com/forums/showthread.php?t=19780

adikt
11-07-2006, 09:18 AM
it is common for tap water filtered with rodi to have a low ph. if mixed with salt a day or 2 in advance and well aerated and still has low ph then add enough buffer to correct. usually proper aeration will get you close if your using a high quality salt mix.

So for top off water I should buffer?

I'm using Tropic Marin Pro Reef so I should be fine as long as I mix in advanced and aerate?

Sorry new to the whole make my own RO water game. Used to get it at Wal Mart then LFS... but now I'm trying to take more control of the system.

chris&barb
11-07-2006, 09:48 AM
you dont need to adjust the PH of top off water. when water evaporates from your tank, all the salts are left behind so no need to adjust it.

if your tank PH is really 7.6 you have something else going on.

can you please post the results from every test kit you have? and also tell us what test kit you are using.

DonW
11-07-2006, 10:50 AM
you dont need to adjust the PH of top off water. when water evaporates from your tank, all the salts are left behind so no need to adjust it.

if your tank PH is really 7.6 you have something else going on.

can you please post the results from every test kit you have? and also tell us what test kit you are using.


I agree, you dont need to buffer rodi water. You could try to patch the problem with kalk, which should help. Its more likely a nutrient or high co2 problem. Your in the same boat as the rest of us. I'm sure you house is closed up pretty tight with the heat on since it hasnt stopped raining for a week now. Winter is a time that you realy need to keep nutrient levels low and water circulation high. Try opening a window or two and see if it helps your ph. That will help point you in the right direction.

Don

adikt
11-08-2006, 01:40 AM
you dont need to adjust the PH of top off water. when water evaporates from your tank, all the salts are left behind so no need to adjust it.

if your tank PH is really 7.6 you have something else going on.

can you please post the results from every test kit you have? and also tell us what test kit you are using.

i tested pH with Hanna pH Checker @ 7.74 currently and my sG is @ 1.025.

Calcium: 375~400 mg/1 (Ca) using Aquarium Systems

I do a 25% weekly water change with Tropic Marin Pro Reef (using my RODI water)

The tank is a 16g tank with a 25 gallon refugium (loaded with chaeto). I run the fuge light cycle inverse of the main tanks display lights.

Also run a Corallife Super Skimmer 65 24/7.

Tanks been up for 1.5+ years and never had a pH problem until I started to use my RODI water.

chris&barb
11-08-2006, 09:29 AM
what is your ALK?

as stated above, dripping a little kalk will help

DonW
11-08-2006, 10:28 AM
i tested pH with Hanna pH Checker @ 7.74 currently and my sG is @ 1.025.



I'd question the accuracy. Has this meter been calibrated lately? It takes alot of c02 to get ph that low.

Don

Boomer
11-08-2006, 12:48 PM
I agee wiht Don & Chris. Also IIRC that meter does not have ATC so check the pH at or around 77 F. CO2 Yes Don, like 8-10 X normal seawater. He is close to 3-4 ppm and NSW is 0.40 ppm

jsmkmavity
11-08-2006, 09:50 PM
if your top off water is not fed automatically you could aerate it if it is low, but the real concern is the tank so find what is causing the tank to be low. is the meter accurate and have you ever tested with salifert or other high quality MARINE ph test kit? do you have good surface movement of water on the top of the tank to allow proper air exchange? are you overstocked or overfeeding and or under-cleaning? does the room with the tank or the rest of the house have good air infiltration from outside? if the house is low on o2 and high in co2 the tank will be too! in the northern climates we tend to shut our house up a little too much to save heat and money but starve the inhabitants of oxygen. hope this helps,and remember to have fun.

Boomer
11-09-2006, 12:07 AM
Adikt

Have you added any Purple-Up by chance

adikt
11-09-2006, 09:17 AM
Adikt

Have you added any Purple-Up by chance

Nope, I've never done any additives in the past year.. just my regular weekly water changes.

As for feeding I feed frozen foods every couple days... sometimes every 3-4 days.

I do DT's a few times a week - no real set schedule. There is enough surface agitation... not to mention the skimmer (which should inject o2 into the water). It's hard to say whats going on.. I wish someone who knew all about water chem. could come over and take a water sample..

Boomer
11-09-2006, 12:14 PM
Take a L of water and put it outside with an airsotne in it and let it aerated for a few hrs and then take a pH reading.

reeftank1
11-13-2006, 09:29 PM
Are there covers on the tank? That was a big, dumb, simple mistake for me.