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Frogspawn 03-02-2007 07:16 AM

PH problem
hey guys need help with this Ph problem i have. i bought a 20g rubermaid tub from walmart last week and i put about 15g of distilled water from food lion in it. then i added 1/2cup per gallon of reefcrystals to it and then put my 100watt heater and a maxi jet 1200 PH in there to mix and airate every thing. i got thinking and tested my PH, ammo,nitrites and nitrates and phos. and all were at 0ppm. except my PH was at 8.2-8.3.
now a day later i tested only my ph to see if anything changed and it did. it went down to 7.6 mabey lower its a weird color. almost like a ornge brown (very wierd) but this always happen to me . ever since i started this SW hobby i have never had a PH of 8.2 last longer then a few hrs and thats only when i mix up a batch for a partical water change.
now i know u guys are going to say add buffers. i been that route too with my 55. i went out and bought a 2lb kent marine buffer and i slowy added that every time my PH got low. i dont want to go that route with this tank. i know its not normal to keep adding buffers every few hrs just to keep up the PH. plus when the PH fall to 7.4-7.6 and then just shoots up to 8.2-8.4 thats cant be good for the fish. :oops:
and all this happens in my rubermaid tub and my Aquarium. it dont matter where i do it. i though the LR i have and the sand would buffer it naturaly but i was wrong. i guess. i do have ha power head pointed to the top for good surface ripple
what can i do to fix this problem. and what could be causing this to happen?
thanks again guys

tecwzrd 03-02-2007 09:37 AM

7.8-8.5 is fine as long as it's stable. Adding buffers helps if alk is low but if within normal range I wouldn't mess with it.

Reef Crystals is a pretty good brand so I'd double check your 7.6 reading (which is hard to tell with AP) which is most likely off and I would check that against another brand or with your lfs. Test kits do expire as well which could be the issue.

Also its very normal for ph to be in the lower range with newer tanks and will stabilize in the higher 8.0+ range over time.

Couple of good articles on chemicals in the tank:

A Simplified Guide to the Relationship Between
Calcium, Alkalinity, Magnesium and pH

Solving Calcium and Alkalinity Problems

Chemistry and the Aquarium: What is Alkalinity?

Chemistry and the Aquarium: Calcium

roka64 03-02-2007 09:39 AM

PH comes from O2 exchange, which happens at the surface of the water. Do you have a ph pointing near the surface to cause surface ripple? Also, keep in mind pH swings between lights on/off. Make sure you measure it around the same time everyday.
That is a big swing, stability is what we want, even if the pH happens to be a little low.

Ziggy953 03-02-2007 11:05 AM

I totally agree....buffering the PH right now may be a bigger problem then a lower PH. Allow you tank to mature a bit more, like Micah said.

Kurt_Nelson 03-02-2007 11:41 AM

Somethings up, but I'm not sure what it is. Might be the air exchange thing roka mentioned, but you say it's happening in your tank too. If you have the lid on the rubbermaid on tight, that could be a problem. Also if your tank is covered tightly, that could be the problem too.

I use Reef Crystals also, with DI water. It usually mixes up to about 8.2-8.3 pH and a alkalinity of 8 dKH and will stay that way for a week until I use it for a PWC. The alkalinity might drop a bit, but not much.

tecwzrd 03-02-2007 12:01 PM

I'm thinking its closer to what Scott mentioned about measuring it at the same time for comparison purposes.

PH is highest at night just before "lights out" and lowest first thing in the morning so if it was measured first thing in the morning it could explain for the "wild swing".

Also it looks like the tank might be covered and the tub is covered which traps carbon dioxide and keeps oxygen from exchanging which will lower PH dramatically.

roka64 03-02-2007 12:08 PM

Oh yeah, good catch on the coverings, on both the tank and container.

rubikcube 03-02-2007 12:16 PM

A few notes...

1. pH isn't affected by O2 concentration.
2. pH is affected by CO2 concentration. When CO2 is dissolved in H2O, it becomes carbonic acid. This lowers the pH.
3. CO2 is absorbed during photosynthesis. Thus the longer the lights are on, the more CO2 is absorbed. The less CO2 in the water, the higher the pH.

The covering of the tub shouldn't affect the pH because there isn't any source of CO2 inside the tub. Therefore, the CO2 concentration shouldn't change when the tub is covered.

I would definitely check your alkalinity in the water change water. Otherwise, I would guess that it might be a testing error. Is it possible to verify with an LFS or some other testkit?

roka64 03-02-2007 12:34 PM

In SW, the pH is greatly effected by gas exchange. This gas exchange happens when there is surface ripple. I'm not sure I am following you on the photosynthesis part, or how it would effect premixed SW, in a covered bucket. Maybe I am just not reading it correctly.
I bet, if he took off the lid and cover, it would make a difference. At least that is how I got my pH stable (at 8.2), after I took off the lids.

tecwzrd 03-02-2007 12:49 PM


Originally Posted by rubikcube
The covering of the tub shouldn't affect the pH because there isn't any source of CO2 inside the tub.

The source of CO2 could be right in the home when mixed. If the container is covered it has nowhere to go.

Also IME a covered pwc container has consistently lowered my PH level but I'm not sure the exact causes.

rubikcube 03-02-2007 01:07 PM

My point is that the pH shouldn't change in a covered bucket due to gas exchange because there isn't any gas exchange in a closed system. In any case, it definitely shouldn't change by that much, even with a very high concentration of CO2.

Devilishturtles 03-02-2007 01:26 PM

I agree with Micah, Kurt, and roka64. A closed tub/aquarium promotes the build up of CO2 (or just prevention of the loss of it) and the loss of O2, which is why open systems are preferred. The article that Micah linked by Farley-Holmes is pretty good at explaining the importance of open air.

Could it cause a drop from 8.2 to 7.6? I don't know, but it might be something to look into, definitley, before you try anything else.

Frogspawn 03-02-2007 03:54 PM

thanks guys the tank is not coverd the whole way. the lid that came with the te tank has a another peice on it as well i took off the part that flips up. so what i am left with is a peice of glass about 6inchs long . i place that right under the light to help out so i dont get sw splash on the new light. as far as the ruber maid tub being closed it is empty there in that picture. i pour all of the water i had in the tank befor writing this post.
i have not added anything to the new tank no buffers no nothing. i am going to give it a wile an see what happens i am placeing the LR in there tomarrow and flixing my Refuge problem
so i will give it a week to see if the PH stablizes any.
thanks again for all the post.

MT79 03-02-2007 04:04 PM


now i know u guys are going to say add buffers. i been that route too with my 55.
Reef Crystasl already has 4 meg/l Alk which is more than enough. Buffering will only affect PH temporarily depending on what's used. It is very possible you have a lot of CO2 bult up in your house. This is most common in the winter when the heaters running and the windows are kept shut. Try placing a sample of the water your testing outside w/ a little airation/circulation. If the PH goes upto normal range after an hour or two, you know it's the air in the house cuasing the ph problem-assuming your turnover, surface aggitation are good.

MT79 03-02-2007 04:09 PM


pH isn't affected by O2 concentration.
A drop in O2 will cause a drop in PH. Having good air exchange prevents the drop in O2.

tecwzrd 03-02-2007 04:32 PM


Originally Posted by Frogspawn
i will give it a week to see if the PH stabilizes any.

FWIW tanks can sometimes take months to fully stabilize when it comes to PH.

rubikcube 03-02-2007 05:37 PM

I know it seems like I'm splitting hairs, but the difference is important. O2 has nothing to do with pH. An aquarium with inadequate aeration usually has an excess(when compared to the atmosphere) of CO2 due to fish respiration. When you aerate, the excess CO2 is driven out resulting in a rise in pH.

Frogspawn 03-02-2007 05:48 PM

ok. i am going to buy a maxi jet 900 today maybe even 2 of them. going to have one pointed at the top for a good surface ripple for O2. Now. lets say i do have a high source of CO2 in my home. how could i fix it in my Aquarium? i heard plants use CO2 to grow. is this correct? if so i will put some in my refuge.(i was going to any way)

Has any one else had a problem with keeping there PH stable?

also i will take a sample of water to the Local fish store tomorrow and check my test kit against theirs.

MT79 03-02-2007 05:55 PM

The easiest way to lower the CO2 is to open a window close to the tank for a few minutes periodically. If that doesn't work or is not possible, other more involved solutions may be needed.

MT79 03-02-2007 06:03 PM


i heard plants use CO2 to grow. is this correct? if
Just about anything photosynthetic does. That is why PH increases when the lights are on-Co2 levels decrease. That is not a long term solution, you will still have the PH issue.


Has any one else had a problem with keeping there PH stable?
Yes at first. As tecwzrd pointed out new tanks will have low PH, but your make up water should be fine. That is why I think you may have high Co2 levels in your house.

Frogspawn 03-02-2007 06:10 PM

i am going to open the windows for today and tomarrow. its suppose to be nice out. so i hope it fix the issuse. thats smart of u to think that. i would have never even guess it.
i hope it works

MT79 03-02-2007 06:22 PM

I actually had the same issue when I was getting started. Still occasionally I'll notice my tank looks off, and I know 99% of the time it needs some air. if I don't open a window every once in awhile it will get down to 7.8 or so. I'm just passing on the knowledge I received :wink: HTH

Frogspawn 03-03-2007 07:44 AM

i have had a window cracked all day and all night and i think it might have went up some but i checked it at the wrong time. (bonehead) when i check it the light just came on and it was about 7.8 from what i could tell. and u guys said the PH is at its lowest when the lights first come on so i will check it tomarrow some time.

Frogspawn 03-06-2007 08:44 AM

ok its been a wile since i posted on this thread last and since i have had my window cracked for a few hrs a day and still i cant seem to get my PH above 7.8. now i know u guys siad new tanks seem to run a little low. and thats ok. but would putting a frogspawn coral in there hurt any. its my faviort coral of all lol :) how should i go by it?

tecwzrd 03-06-2007 09:19 AM has a good article on them. They require a well established tank and excellent water parameters though so I'd hold off a couple of more months for your tank to stabilize more.

Any coral like fish/inverts can adjust to a lower ph of 7.8 but requires a slow drip acclimation to do so.

Have you taken a sample to the lfs to test or bought a new PH test? What are your day/night readings?

Frogspawn 03-06-2007 04:47 PM

i just took a reading this moring right befor light came on and it was a little lower then 7.8 mabey 7.6-7.7 kinda then last night right befor lights went off the reading was 7.8. how cn i fix this problem?

roka64 03-06-2007 04:51 PM

The tank is still cycling right? If so, I wouldn't worry about the pH yet, as it takes some time to balance out, in newer tanks.
Did you remove the glass top?
Remember, the pH will be higher before lights out and lower right after lights on. As stated before, if you can keep it stable, that is best.

MT79 03-06-2007 04:59 PM

7.8 or a little lower is not too uncommon after lights out for tanks not dripping kalk at night. I run at about 7.8 at night even w/ a fuge full of macro-algae on a reverse lighting schedule. However after the lights have been on for a few hours you should at least hit 8.0 ph IMO. I think the next step would be to take a sample of tank water outside and put an airstone in it. Check the PH after an hour or so. If it goes up substantially it's most likely the air in your house. If not, the tank/LR may just need some time to mature.
FWIW a tank generally is not considered mature until a year or so after the initial set up. Let us know what happens w/ the sample.

Frogspawn 03-06-2007 05:58 PM

i cycled the LR in a different tank. and when it was done i put in my new tank. as for the glass top its open for the most part. i just have a little 6 or 7 inch peice of glass covering where the light is so i dont get salt splash on my new light. i will take a sample out side and let u guys know whats happen. i get back to u on that.

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