Water hardness and PH adjustment...

[WBrian]

Hi All!
Question, I've recently set up a 29 Gal salt FOWLR (currently, but reefing it some day!). My PH has been dropping every day down to the 7.8 range! The fish don't like this very much!! My salinity was high last night so I did a fress water (RO) exchange of 3 gal, and that seems to have corrected the salinity.

Anyway, I took some water in to the LFS last night for them to check my calcium and hardness. My PH was OK (8.2) at that time as I had corrected it earlier in the day. My ammonia, nitrite and nitrates are @ zero. But my hardness (I think they said KH? ...or carbonate hardness??) was way low. I don't rec all the actual number this morning, though. They also checked my calcium level, and it was somewhat low, but they made no suggestion on correcting it. Again, I don't recall the number.

Well, like I said, yesterday I corrected the PH using "Kent Marine Super Buffer DKH", one teaspoon in water and apply to tank ( as label said). PH improved, as several hours later it was in the 8.2-8.3 range. (I wanted to give it time to spread out through the tank. Well, this AM I get up and decided to check it again. Well the PH is back to 7.8. This has happened for several days, now. I just reapplied the Superbuffer DKH.

The LFS guy says that in time, my KH will raise enough to not need the buffer other than when I do water changes or the occasional adjustment.

I am using "Aquarium Pharmaceuticals Saltwater Master Liquid Test Kit" to check my PH, ammonia, nitrite and nitrate levels.

Any suggestions on how I can raise the hardness of the water quicker? (or is that hazardous to the livestock?) How about a way to get the PH to stay up?

Is this Superbuffer DKH a quality product? Is there something better/faster/...?

Thanks from me and my fishes!
Brian

 

[ChrisRD]

Although some daily pH fluctuation is normal, I would check to see if you're getting a build-up of CO2. If you've got a cover on the tank that doesn't allow for adequate ventilation, if you've got poor circulation, or just a lack of water surface agitation you may be getting poor gas exchange. This can cause problems with low system pH.

An easy way to check this is to take a cup/bowl of tank water and test the pH. Aerate the water for a couple of hours and then test again. If the pH goes up, your low pH problem is probably due to poor gas exchange. Increasing ventilation/circulation/surface agitation will likely improve this situation. One of the benefits of running a protein skimmer is also increased gas exchange.

Another issue that can cause pH problems, especially in tightly sealed/insulated modern homes, is high indoor CO2 levels.

 

[Anonymous]

Brian,
I think what your seeing is a CO2 build up. Can you get an airstone into about a cup's worth of tank water for say an hour or two? pH test before and after. If the pH goes up you need more oxygen in the tank. You can point a ph at the surface for some aggitation and that will help. You'll see your pH stablize.

 

[WBrian]

OK, so I did the airstone in a glass of water for 2 hours. My PH changed from 8.0 up to 8.2 - 8.3. So I put a powerhead in as suggested. How should I set it? Is it mostly to make turbulence on the surface? Or should it be adding bubbles to the water? I'm trying to figure out how to adjust it, but it seems to make a bunch of little bubbles in the water, whatever I do.

How long would it take to see a change in the PH of the tank with this going? My clownfish looks exhausted, and I'm worried about him.

Thanks!
Brian

 

[ChrisRD]

Aim the powerhead at the surface. You don't need or want the little bubbles as they'll cause salt creep. If there's an air intake line connected to the powerhead, remove it (no air intake = no bubbles).

 

[WBrian]

OK,
So the PH is moving water real well. (The fish seem to be going upstream wherever they are in the tank!) I've had it going since yesterday afternoon. My PH was back to 7.8 this AM (ammonia, nitrite and nitrate remain zero). So I'm stricking with the "Superbuffer DKH" unless there are any other suggestions. The directions say to add 1 teaspoon for every 80 liters. I've got a 29 gal tank, but there's a good bit of rock in there, too.

Do I dose for the full 29 gal?

Would it be better to split to dose into an AM and a PM dose to keep the PH more moderate throughout the 24 hour day?

Thanks for the help on this.
(Next I'll be asking how to get rid of the horrible emerald green stuff growing on my sand/crushed coral base!)

Later,
Brian

 

[ChrisRD]

Your pH is on the low side, but not crazy low IMO. A pH of 7.8 should not be harmful to your fish. It may be an indication of a problem (worth continuing to look into IMO) but I wouldn't go too crazy chasing the numbers. Personally, I would not blindly dose buffer based solely on pH readings without monitoring alk levels. Ca and alk go hand-in-hand and if you're dosing one without the other you may be creating an imbalance.

Do you have a cover on the tank? If so, how well ventilated is it? If the outside air is not exchanging well with the surface of the tank water the off-gassing problem (or lack thereof) is still not completely addressed.

 

[WBrian]

Thanks Chris,
I had taken a sample to the LFS previously. They said my carbonate hardness was low, and that the buffer would correct that and resultantly my PH would improve. I am planning on taking some water in again tonight and I'll get actual numbers to post here.

Thanks again,
Brian

BTW, I have a glass top folded in half, in about the middle of the tank. So it's open in the front and the back. I'm just trying to cut down on the salt creep on the lights until I can get around to making a canopy to support the lights...

 

[WBrian]

OK,
back from the LFS.
My PH was 8.0, but remember I added the superbuffer DKH this AM.
My Ammonia, nitrite and nitrate were zero.
My KH (carbonate hardness?) was 5 (degrees) where normal is 15-20.
My calcium level was 220 (norm 350-400 range).

The guy at the LFS sold me some "Reef Carbonate" by Seachem. He said it will raise my KH.

The label says: "Reef carbonate is a concentrated (4,000 meq/L) optimized blend of carbonate and bicarbonate salts designed to restore and maintain alkalinity in the reef aquarium. Calcium and carbonates are essential to all ..."

"...Used as directed, Reef Carbonate will not deplete calcium, magnesium, or strontium which usually tend to precipitate with increasing alkalinity. Reef alkalinity should be maintained at 4-5 meq/L (11-14dKH). Alkalinity should not be allowed to fall below 2 meq/L."

SO still the clown doesn't eat, and is looking poorly. It might have just had too much stress. We shall see.

Later,
Brian

 

[ChrisRD]

If Ca and alk are both low I'd recommend adding them in balanced ratios. If you start trying to dose separately you'll drive yourself crazy IME. Kalkwasser (limewater) adds Ca/alk in balanced quantities and is very cheap (especially considering you can just use food grade pickling lime from the grocery store). It also raises pH though, so you need to be cautious with it.

In reef tanks it's common to use kalkwasser to top-off evaporation to kill two birds with one stone so to speak (evap top-off + Ca/alk supplementation). With a tank like yours that would have very low Ca/alk demand (no calcifying corals yet - probably just some coralline algae) you wouldn't want to use anywhere near the saturated solution some reefers use - just a little bit of kalk mix (pickling lime) in your top-off water. I've done this myself with FO tanks and it works well. Something to consider...

 

[WBrian]

Thanks Chris,
I'll check out the pickling lime (kalkwasser). I've already started treatment with the Reef Carbonate stuff, so I might see how that goes for a a week. Unfortunately the clown didn't make it through the night. I even tried some live brine last night to get her to ewat, but no go. So all that's left in the tank are my flame angel and the CBS. Both of which seem to be doing well.

Here's a pic of the green stuff on the bottom of my tank, BTW...

and here's a wider shot...

The LFS guy says it's green algae and should improve after the KH is corrected. think so?

Thanks again,
Brian

 

[ChrisRD]

Sorry, can't see the pic...

 

[WBrian]

Hi Chris,
The first image is at
http://img.photobucket.com/albums/v448/ ... nalgae.jpg

The second is at
http://img.photobucket.com/albums/v448/ ... bottom.jpg

Thanks for all your help!
Brian

 

[ChrisRD]

OK, from home I see the pics from the first post so it must be something to do with the browser security at work...

Anyway, it just looks like a green film algae to me - some snails would probably make short work of that. It's pretty normal to see a few different types of algaes come and go in the first few months the tank is up.