Wondering about my KH value

[An t-iasg]

As I plant my tanks more heavily than they were before, I'm wondering if my KH is going to be ok. Well, it's probably not and overnight I don't want the pH to swing. I read that you can add baking soda to raise KH without affecting pH, but the amount that I would need is something like less than 1/8 teaspoon per gallon, which is pretty hard to measure accurately. The KH is 1dKH, the GH is 4dGH, and the pH is 6.8. Add the overnight pH swing possibility and possibly the Seachem Excel's affect on pH and I'm uncertain on how to proceed.

 

[greenmaji]

I have absolutely no experience with the Excel product.. So Im going to go with the rest of the information you have in your post..
you are probably on target with being consered with a possible PH swing.. Do you have CO2? If not I would worry more about my O2 levels, plant respiration and all..
The added acids from the new plants shouldnt be alot more than the acids involved in your system before they were added.. how often and how big are your water change's?
If your doing 30%+ pwc's every other day then dont worry about it.. If you pwc's are fewer and less % then I would suggest that you check your PH an hour before the lights come back on and see if there how much the PH is effected..
My only concern is the amount of new plants in your tank you have added alot more than you had but from my understanding the acids added by plants have less of an effect on PH swings then the nitrification acids..

 

[An t-iasg]

More info: the values above were from the tank. I use half tap and half RO.

The plants right now are still in critter keepers, in tap water. I tested the pH of the water in the critter keepers: pH is 7.2 in one and 7.4 in another, down from 7.8. So it seems like the pH falls with the addition of the plants, but the fish are used to the mix of tap and RO. Hmmm. I'll test the pH of the critter keepers again in the morning before I turn the lights on. Since I'm not injecting CO2, will the morning value matter, or be any different from the evening value? It should change, right, since the plants take in O2 at night? Yes, this is making me batty

 

[greenmaji]

On the other hand you can always under dose the baking soda! ROFL

 

[greenmaji]

In that case why dont you slowly acclimate the fish to a lower dosage of RO..?

 

[greenmaji]

since the plants are taking O2 in at night my best theory would be that the PH would be slightly lower.. more CO2 in the water from it not being consumed.. make any sense? the CO2 should only be 3-4ppm at most without injection so the swing shouldnt be that significant..

 

[An t-iasg]

In that case why dont you slowly acclimate the fish to a lower dosage of RO..?

Yes, I considered that too. That may be the easiest in the long run, and it could be done slowly.

the CO2 should only be 3-4ppm at most without injection so the swing shouldnt be that significant..

I wondered about that too -- since I don't inject CO2, maybe I'm worrying a bit for nothing...we'll see what my morining pH is.

 

[greenmaji]

Your situation will defiantly proof the theory..

 

[Steve Hampton]

As I plant my tanks more heavily than they were before, I'm wondering if my KH is going to be ok. Well, it's probably not and overnight I don't want the pH to swing.

I wouldn't be as concerned about an overnight swing as I would about having a dramatic drop to a very low pH that stays low.

I read that you can add baking soda to raise KH without affecting pH,

Actually you can't. If you add baking soda (sodium bicarbonate) you have increased the KH or bicarbonate buffer and the pH will rise...the amount of the rise is dependant on the increase in the KH, but if you increase your KH from 1 to 3 you will see a rise in pH too. You could add a very small amount of baking soda and not be able to see the rise in pH with a pH test kit, though it would show with a good pH meter. Adding baking soda will not increase the GH reading...although the TDS has increased. For some soft water fish the increase in sodium is worse than an increase in calcium and/or magnesium (the hard water constituents). But for most fish the slight elevation in sodium is unproblematic.

Seachem Excel's affect on pH and I'm uncertain on how to proceed.

Excel shouldn't have any effect on pH.

Some important points to remember:

CO2 concentration in an aquarium doesn't depend on the other things dissolved in your water. (many folks think O2 levels and CO2 levels are linked...they are independant of each other)

KH is the amount of bicarbonate

pH is always set by those two (CO2 and KH)

A stable pH depends on both being present in reasonably comparable quantities.

Plants CAN'T remove KH if the GH is low. When plants do remove KH the pH becomes very high (8 to 10) and a deposit of calcium carbonate forms (biogenic decalcification) and both GH and KH drop.

So, generally speaking, plants during photosynthesis will remove CO2 from the aquarium water, removing CO2 will cause the pH to increase (CO2 forms carbonic acid...a pH lowering acid uneffected by the buffering mechanics that KH has on other acids). Fish respire ammonia/ammonium from their gills, combined with solid wastes being broken down by bacteria an you have lots of nitrification depending on the number and size of the fish and the amount and type of fish food given. Meaning, it's fairly easy to overwhelm a low buffer with the acids produced within the tank. Healthy plants generally help remove acid cause issues within a tank...but new plants that may not be healthy can and do exacerbates the nitrification problems.

 

[malkore]

I can second Steve's comment that Excel doesn't alter pH whatsoever. It does seem to decrease O2 levels in the water by no more than 1ppm, and within a couple hours it's gone.
This of course assumes that the Excel doesn't just mess up an O2 test kit

 

[An t-iasg]

Thanks, Malkore! My morning pH was unchanged -- still 7.2 and 7.4. This measurement was taken in the critter keepers, where the plants are now. Tank #1 is still unchanged (no new plants in yet) and Tank #2 is not set up yet. The new betta is still in a 2 gallon QT, with heater and filter, but he will go into the 5 gallon this weekend.

It would seem that using tap water would be the best way, instead of my tap-RO mix, since I used tap to fill the critter keepers and now the pH is more reasonable than the 8.2/7.8 after aging. The plants alone lowered the pH, then. The KH and GH of each critter keeper is --
C.K. #1: pH 7.2, KH 2, GH 10 (that seems high)
C.K. #2: pH 7.4, KH 3, GH 9

Now I just have to acclimate the fish correctly.

 

[greenmaji]

How are you going to acclimate the fish that are in the tank.. small pwc's with tap?

 

[An t-iasg]

Yes, I already got the gallon jugs ready this afternoon so they can age for about 24 hours. For the new fish, still in QT, I made up half and half tap and RO for him since that is what he has now. I will get his tank built tomorrow, and next Wednesday I'll do a water change of 1/2 gallon aged tap water. Half a gallon into the 5 gallon will be not stress him, hopefully, and the plants will need the buffer. For the fish already in a tank, I made up a water change jug (one gallon) of 2/3 tap and 1/3 RO to get him gradually used to a little more tap water. I'll do that water change on Saturday when I put his new plants in. This fish is also in a 5 gallon tank. That pH is 6.8 -- not bad, but when I put the new plants in tomorrow, they will need more buffer. I will have to do water changes probably twice a week -- one a normal water change, and another a small water change with aged tap water, all the while gradually mixing in a little more tap than RO for the weekly water change. I just wish I had a digital pH meter right about now!

 

[greenmaji]

I would be wanting a drip water change system about now!!! LOL..
You are definatly going on the cautious side.. hope your acclimaion period isnt so long that it drives you nuts!

 

[An t-iasg]

Yes, I'm being cautious because I love my fishies!

I could start putting a little more tap water in the new tank tomorrow, but I'm going to start it with half and half tap and RO, like the existing tank is right now. That way I can kind of acclimate them to a little more tap together -- I can make one gallon of aged tap water and split between the two tanks. That way hopefully I won't go too crazy if I'm doing the same change routine for both tanks!

If I knew someone with SW tanks who had a TDS meter, pH meter, or drip system, that would come in handy!

 

[greenmaji]

Using the same container of aged water is fine.. are you positive your area hasnt switched to clorimides by the way? A few around here are in the middle of the switch right now..ack.. they need to announce that some how!!
a small gravity fed drip system wouldnt be to tough to design and implement but I personally think your situation right now isnt ideal for that kind of work..LOL
On the other hand I have ideas in my head if you have the extra time....
by the way I forgot how big the other tank(s) is/are..