WHY is my pH so low?

[misskeeter2766]

7.2..... why?

I have been doing PWCs every 4 days. I change 1.5 to 2 gallons out of my 12 gallon nano cube... I use fresh saltwater from the lfs that is made with RO water and instant ocean salt...

pH will be fine when I first add the new water, then a day later.. it shoots down... it is going lower and lower... this is the lowest so far...

what should I do? what could be causing this?

other params are...

ammonia-0
nitrite-0
nitrate->10
alk-300
phosphate-0
salinity-1.025
temp-78 (lowered it because my zoas weren't opening... some are now)

toadstool leather, feather duster, 2 zoas, 2 mushrooms, 2 scarlet hermits, 8 cerith snails, 8 nassa snails, emerald crab, a few hitchhikers that I know of... some little brittle stars and a couple of what appears to be peanut worms?.... lights are 2 pc 24 watt 50/50... 20 pounds of live rock including rubble... stock flow... carbon (should I remove it?) and removed the sponge and replaced with filter floss in the first chamber
tank is one month old.... pH starting dropping when I added my new frags... added 7... I think 4 are dead

 

[misskeeter2766]

oh... also have 18 pounds of live aragonite sand...

 

[mfdrookie516]

got anything covering the top? poor gas exchange can cause the ph to drop... you might try aiming a powerhead towards the surface to get more agitation and make sure that if you have a hood or glass tops that there is plenty of room for air to get in and exchange at the surface of the water

 

[misskeeter2766]

hmm... I might have it filled too high?
it's a nanocube dx... so there's a hood onthe top... I have it filled pretty high.. wonder if it is TOO high...
*going to remove some water.

 

[mfdrookie516]

if you're not running a powerhead, dropping the water level down some so that the filter creates more surface agitation should help.. if it doesnt, i dont know what to tell you, but it should

 

[jcmelski]

Where do you have the tank? I have the same problem except my ph doesn't get that low. I read that excess CO can cause the ph to go down low. All my parameters are perfect. I would do a water change then a day or two later my ph would drop again. Try opening a window to let fresh air into the room where the tank is. BTW what are you using to test the PH? when are you testing it?

 

[misskeeter2766]

I have the tank in the living room.. on an inside wall, opposite two windows that are heavily curtained to keep algae from blooming. I'll try opening a window... I am using a test strip for the pH.. most others are liquid... I usually test in the morning while the lights are still off.. but I've tried nighttime while the lights are on too.

 

[jcmelski]

STOP using the strips!!!they suck big time!! Get yourself a liquid test kit for the ph. make sure it's not expired or close to expiration when you buy it. I use two liquid test kits for my more important tests. That way I can compare the two results. I had super high nitrates with one test kit so I bought another and did a test. the second test kit(also API) showed I had lower nitrates than what I thought I had. Get yourself an RO/DI unit for your home. It will be cheaper in the long run and you can monitor your TDS. Have you tested the fresh RO water from your LFS? What is the ph of the fresh SW once it's mixed? Are you aerating the RO water for a couple hours before mixing the salt? How long are you mixing/aerating the SW for? The problem I have is my freshwater container and my mixing container are in my basement next to my hot water heater. In oder for you to get an algae bloom you have to have high nutrients in your tank first. try doing a 4g water change to see what happens. but first get a liquid ph test kit.

 

[misskeeter2766]

okay... liquid pH kit....

and the water is actually MIXED by the LFS... they use RO water and they mix it... they have it running in a big system... no way can I get my husband to spring for an RO/DI unit for our home right now... the ready saltwater from the lfs is 99 cents a gallon...
I'll get the liquid kit.. then do the water change and see what happens..

thanks.

 

[jcmelski]

WOW only .99 cents! I wish I lived outside on NJ! Everything here is so d!@# expensive. Do a bigger water change to see if that helps to and let us know what the liquid test kit tells you.good luck.

 

[ccCapt]

I would say it's definitely a testing error. If your pH was actually 7.2, nothing would be alive in the tank and your aragonite sand and calcium carbonate live rock would start to dissolve.

 

[misskeeter2766]

I will be getting a liquid kit today...

 

[misskeeter2766]

WOW only .99 cents! I wish I lived outside on NJ! Everything here is so d!@# expensive. Do a bigger water change to see if that helps to and let us know what the liquid test kit tells you.good luck.

yeah... it's a pretty great deal... they sell the RO water for 49 cents a gallon... They are crappy with fish and corals.. but they have a great deal on saltwater. LOL...
I got 8 gallons of saltwater and 2.5 gallons of RO water yesterday for $9.15 ....

 

[ccCapt]

You can get an good RO/DI unit for $100. Have you bought 100g of water from them yet? If so, your RO/DI unit would have been paid for by now.

 

[misskeeter2766]

lol... no... I've only purchased about 30 gallons...

you forget I still have to buy the salt... so it would take more like 200 gallons LOL

 

[ccCapt]

OK..it's your money and you can waste it as you feel necessary.
FYI.....a 200 gallon mix of Instant Ocean costs $40.

So, initial start up cost for RO/DI and 200g salt = $140 for 200g
Water from LFS = $0.99/gal or $198 for 200g

2nd batch of 200g salt = $40
2nd batch of 200g from LFS = $198

After 400g, you paid $180 for an RO/DI and salt or you paid $396 from the LFS.
Seems like a no-brainer.

 

[misskeeter2766]

If I show those numbers to my hubby, he will likely take a hammer to my tank.. LOL..

I do plan on buying a unit as soon as I can... will probably wait a couple of months though.

(I will be getting a MUCH larger tank once we buy a house in a couple of years....)

 

[misskeeter2766]

if I WERE to just bite it (get myself in trouble) and get a unit now...

what is my cheapest (yet still effective) option... I don't want to do any crazy plumbing stuff, because this is a rent house... I have no problem just hooking it up to the sink and running it when I need water then unhooking it...

so???