Ph Shock In co2 injected Planted tank

[J]

How would you go about doing water changes in an aquarium that has...

Tap water that is

1deg KH
PH 8.2

So soft and basic, adding alkaline buffer (same as baking soda) to raise KH, then co2 injected.

8degKH
ph 7.2
15 mg/l co2.


My question is, during water changes how can I avoid pouring water at 8.2+ ph into my 7.2 tank. Will the tank rebound instantly or as a gradual process as the co2 levels raise back to 15mg/l. How do you plant guys do your water changes without huge ph swings.

Just a concern before I invest in a planted setup. Thanks in advance for your help!

[dan2x38]

I do 50% WCs right from the tap using a Python. I mix up a some condtioner in a bucket with some water than pour it in. Never had a problem. I would not mess with the water.

[J]

The tank will house a single strain of blue moscow guppies. Targetting 7.2 isn't a problem, just when it comes to water changes. I'm concerned for the fish, not the plants.

I need a 3rd tank running anyways, if I dont figure out the water issues I'll just keep a really nice planted tank.

[J]

I do appreciate the quick reply Dan, thanks!

[jrs]

I know this is semantics but there is no such thing as pH shock.  It is osmotic shock that fish can experience.

[fischkopp]

Adding water with 1 pH difference is usually no problem, even for sensitive fish. The best is that you keep an eye on the fish. If the fish acts overly stressed after the water change the you will have two options: change less water or age the water for a day, preferably with an air stone and KH raised already. Like others, I have not had any problem with 50% water changes straight out of the tap, and most of my tanks run with a pH <6.

[charlie]

I know this is semantics but there is no such thing as pH shock.  It is osmotic shock that fish can experience.

Agreed, i remember reading a post by Tom Barr about this, i`ll try & find it to post a link here.

[KLKelly]

I have always been told not to go greater than .4ph change in more than 24 hours.

If PH shock wasn't a factor then why do acclimatize fish to ph and not just temperature when we buy them?

I also discovered when we switched to RO water and I was bringing my tanks down from 8.3 to lower 7s due to ammonia that ph isn't linear.   Meaning if I have a tank at 8.3 and using RO water with ph of 7.0 and do a 50% change you can't just work out what ph will be by dividing by two.  Someone on the thegab.org did a spreadsheet for me and it depends on KH somehow.

[charlie]

Here is a link from Tom Barr's web site on this subject, i think it`s important to note this is relative to PH swings due to CO2 injection.
http://www.barrreport.com/fish-planted-tanks/3587-ph-shifts-fish-health-due-co2.html?highlight=ph+shock

[KLKelly]

AHHHH. Thanks

[blizzack1]

Here is a link from Tom Barr's web site on this subject, i think it`s important to note this is relative to PH swings due to CO2 injection.
http://www.barrreport.com/fish-planted-tanks/3587-ph-shifts-fish-health-due-co2.html?highlight=ph+shock

Great article!

So, does this mean that PH controllers aren't all that necessary for planted tanks?  Or is there a limit to what the fish can tolerate if, say something went wrong with a CO2 setup?

[dan2x38]

When Rusty Wessel gave his talk he said acclimate the fish to the same temp. He said that fish take upwards to 2 weeks to totally acclimate to new water conditions and transporting. he floats the bags until equal temp then dumps them in.

I still worry about sensitive fish like Rams, Cardinals, sensitive inverts and dripline them. Just a worry wort but an once or prevention is worth a pound of cure.

[jart]

So soft and basic, adding alkaline buffer (same as baking soda) to raise KH, then co2 injected.

My kH is non existent. The need to add baking soda to raise kH has been questioned, and no longer deemed necessary, IMO. I'll let others chime in as to what they think, but if necessary I can dig up a link. Baking soda is dirt cheap, but why add something if we don't need to?

For the record, my pH is 6.9 during the night, then 5.9 once the CO2 has kicked in to full gear. This of course takes place on a daily basis. I usually do my WCs before the CO2 has come on.

Controllers may not be necessary, but they do make life a lot easier. At least in my experience.

[J]

More on the relationship of KH CO2 and PH, good read:

http://aquaticconcepts.thekrib.com/Co2/co2_faq.htm

[jart]

That link from the krib is quite dated, sorry to say, and has a few inaccuracies. For example: "Is there a way to reduce pH without resorting to algae inducing phosphate buffers?" In the 1990s, remember, it was thought that excess phosphate induced algae. Now we know that is not the case.

[dan2x38]

I was so confused about the P & N myths when I started into the planted World. Half of what a read said P was causing algae in my tanks. The articles also said that excess N was the culprit too so I did my best to reduce these to low as humanly possible. I had the lighting but could not grow the nicer plants like Charlie's (and mine) favorate 'reneckii'. The leaves dropped and curled then built up with diatoms & green spot algae.

Charlie, Big Daddy, Fischkopp and others pointed me to articles explaining more about the present realities of P & N. I started adding them but was using the PPDM so still testing. But the results were there now. I started adding the nicer more demanding plants. The leaves were not curled, there was no more diatoms or green spot algae. I'd also learned to low of N vr. P caused diatoms.

Grasping the P & N controversy was the difference between rich colours and lush growth. Of course making the pressurized CO2 jump made things even better.

All in all try to stay with the tried and true like Tom Barr, Greg Watson, Rex Riggs these guys know their stuff big time!!!

[J]

That link from the krib is quite dated, sorry to say, and has a few inaccuracies. For example: "Is there a way to reduce pH without resorting to algae inducing phosphate buffers?" In the 1990s, remember, it was thought that excess phosphate induced algae. Now we know that is not the case.

Well my question wasn't about phosphates nor using phosphate buffers. I found the co2 information useful.

Dan, I have read the Rex Grigg pages, they are excellent.

[jart]

Sorry, didn't mean to confuse the issue. There are several inaccuracies in the article; the phosphate one was just the most blatant.

1) "The table is very accurate..." It can in fact be quite inaccurate.
2) "An optimum level of CO2 is 15 mg/l; a good range is 10-20 mg/l." For some folks 15 ppm is fine; for others it is inadequate and will result in algae and stunted growth.
3) "The pH should be set to suit the species of fish you will keep in the tank." Not necessary; may be detrimental to fish health rather than just letting things be.
4) "but keep CO2 less than 30 mg/l, of course"

Edit:
I should add that I am not trying to be critical of anybody for posting a link to try to help others; nor am I critical of the people who spent countless hours contributing to the articles that are available on the Krib. I can remember years ago spending countless hours reading all the information there, dial up modem and all…it was a great resource, just a little dated with respect to some things at present.

[dan2x38]

Yeah if you go heavy ferts like EI method then you will need higher CO2 like 30ppm or algae can take hold. Of course this will affect the CO2 more - lights on for me = 7.2 - lights out = 6.0. Charlie has a tried and true method turn up the CO2 (slowly) until the fish become lazy then just a tiny turn backwards - the fish are the meter. Stay at home when you do it remember the CO2 will be highest end of photo cycle. I lost a couple Rams doing it I thought I'd backed it off enough...

[fischkopp]

the CO2 will be highest end of photo cycle.

Not necessarily: it would only be the highest if there is an excess of CO2 added, if plants deplete it faster then it gets back into the water then it will be the lowest. The goal of course will be keep the CO2 somewhat constant during the day, maybe with a tendency toward depletion at the end of the day.