How To Consistently, And Stability Hold Ph While Using Excel By Seache

So I have a pretty planted 75 gallon tank (10 plants total, 6 of which are LARGE amazon swords), and to maintain the plants I use Seachems Excel, as I cannot afford for a full on CO2 injection system just yet.  Using Excel, I have had great growth in my plants, and my fish all seem very happy.  However, after I add the Excel, the pH in the tank falls to at OR BELOW 6.0 pH.  So my question is, how do I get a pH to maintain at around 6.8-7.2 while using Excel, and without causing any crazy spikes or changes in my pH?  I have tried baking soda before, and mixed it in about a gallon of aquarium water before adding to the tank, and even though I used less than half of what is called for a tank my size, all of my fish INSTANTLY started to freak out, until I did a huge water change to get that out, so baking soda is not a route I want to take again. 

Weird - I thought Excel was not supposed to impact pH at all (just from what I have read - have not used it). What is your normal pH level without having Excel in the tank? Is it normally 6.8 - 7.2?

Yep, your spot on, without Excel, I am almost always right in that nice 6.8-7.2 range.  It is defiantly the Excel, as I read in other forums about it, but not the solution to the issue, as well as that all CO2 type products can impact pH (Excel is a form of carbon for the plants).  On my w/c days, I do not add anything to the tank but my declorinator, and then wait till the next evening to add the plant additives, so in that time, I get a normal pH reading.  However, within a few hours of adding Excel, you find the pH is at the lowest range in the test kit.

I haven't use Seachem - I use Easy Life's Easycarbo and have never had any pH problems. Am learning much more about water chemistry since I started keeping shrimp. Do you know the KH of your water? This would tell you how well your water can buffer any pH drops.

I do not know the KH of the water, as I dont have a test kit for that, which i take it i should look into?  So what does "how well your water can buffer any pH drops" mean?  Im still a newbie in the hobby....

KH is the amount of carbonates that help to stop the pH from dropping suddenly. I'm sure a chemist could explain it better. 
Here is an article I found useful when I was learning more about water chemistry beyond the big 4 (Ammonia, nitrite, nitrate and pH)
http/fins.actwin.com/mirror/begin-chem.html
Hope it helps

Thanks!

Seachem state emphatically on their site that Excel will not affect pH.  Now, I'm not saying this is 100% reliable, but I would look at other related issues too.  And as others mentioned, the GH and KH of your source water (which will presumably be the same as the aquarium or very close unless you are targeting the GH/KH somehow) is critical in determining pH issues as these are all related.  Another reason it is risky to mess with one of the factors.  You can ascertain the GH and KH of your tap water from your municipal water people, likely on their website.  I wouldn't waste money for a kit unless down the road you find it necessary to be adjusting GH/KH.  I wrote an article on all this that you might find useful:
http/www.tropicalfishkeeping.com/freshwater-general-articles/water-hardness-ph-freshwater-aquarium-188705/
I'm no longer active on that site, but I don't think anyone has messed with the text.
 
Sodium bicarbonate (baking soda) is not a safe thing to be adding to an aquarium.  Not only does this not buffer long-term (organics will affect it long-term), there are always risks as you have clearly found out.  A safer course is to determine the water chemistry and biological processes, and work within them rather than against them.
 
Another aspect that is crucial is the fish species.  I don't know why you feel a pH of 6.8 to 7.0 is ideal, as frankly it is anything but, although it is not going to do harm either depending upon fish species.  No water in nature has a pH of 7.0, it will either be lower (acidic) or higher (basic) depending upon what it comes into contact with.  Knowing your fish species will help here.
 
Last on Excel.  This is not the same as CO2.  And as others probably know by now, I do not advocate using this highly toxic chemical.  It is not necessary; the plants mentioned do not need CO2 (beyond what will occur naturally of course), I have kept thriving swords for over 25 years and the carbon occurring naturally in the aquarium has been more than sufficient to balance moderate light.  However, understand that once you start adding chemical substances there is going to be reactions within the aquarium, and all of this is going to impact fish somehow.  It may or may not be detrimental, depending.  The fact that Excel kills some plants outright, and kills some types of algae, should warn us that it has definite risks for fish and bacteria.  It is after all comprised of nothing but a highly toxic disinfectant used in hospitals to kill bacteria and water.
 
Byron.

Very interesting Byron!!
 
With that, I use the Seachem Flourish, Iron, and Trace for my plants.  Now the situation I am talking about is in my 75 gal, that is planted.  However, in my 29 gal, I have no live plants (yet), so i do not use any of the Flourish line in that tank (so no Excel, Flourish, Iron, or Trace) and that tank has no pH issues at all.  Which, being a beginner, is why I thought it must be the Excel, as i seen on other posts people with the same issue stating it was the Excel causing it.  Also I thought Excel was a form of CO2, as it says its an "organic carbon" source.  
 
So are you saying that a good idea would be eliminating the use of Excel all together?
 
in the 75 I have; 6 Angelfish, 5 upside down catfish, 7 Platys, and 6 Cory Cats.  

NewTankGuy said:

Very interesting Byron!!
 
With that, I use the Seachem Flourish, Iron, and Trace for my plants.  Now the situation I am talking about is in my 75 gal, that is planted.  However, in my 29 gal, I have no live plants (yet), so i do not use any of the Flourish line in that tank (so no Excel, Flourish, Iron, or Trace) and that tank has no pH issues at all.  Which, being a beginner, is why I thought it must be the Excel, as i seen on other posts people with the same issue stating it was the Excel causing it.  Also I thought Excel was a form of CO2, as it says its an "organic carbon" source.  
 
So are you saying that a good idea would be eliminating the use of Excel all together?
 
in the 75 I have; 6 Angelfish, 5 upside down catfish, 7 Platys, and 6 Cory Cats.  

Click to expand...

 
Excel is a bit more complicated chemically.  Seachem have tried to explain it so as not to alarm anyone, and this is what they say:
The reason plants need CO2 is to produce longer chain carbon compounds also known as photosynthetic intermediates. Photosynthetic intermediates includes compounds such as ribulose 1,5-bisphosphate, and 2-carboxy-3-keto-D-arabinitol 1,5 bisphosphate. Although the names are complicated, the structures are quite simple (5 carbon chains). Flourish Excel™ does not contain these specific compounds per se, but one that is quite similar. By dosing with Flourish Excel™ you bypass the involvement of CO2 and introduce the already finished, structurally similar compounds. It is in its structural similarity that Flourish Excel™ is able to be utilized in the carbon chain building process of photosynthesis. Simple chemical or enzymatic steps can easily convert it to any one to any one of the above named compounds (or a variety of others).
 
I use Flourish Comprehensive, Flourish Trace and Flourish Iron myself, and have for several years.  Not all tanks get the iron, as it depends upon the plants.  I also need to boost the hard minerals as I have zero GH water, so Seachem's Equilibrium is my product for this, but only in three tanks where the larger swords, Aponogeton and Red Tiger Lotus require this increase of primarily calcium.  The hard minerals in Flourish Comp is not sufficient to supplement very soft water for some plants.
 
As for the pH variance between the two tanks, this may be due to the plants.  Plus the fish loads, water changes, and GH/KH/pH of your source water.  I cannot say more without the data.
 
To the fish.  Except for the platy, you have soft water fish, so lowering the pH to the low 6's is not a problem, once we know why.  But you want it to remain there, not be fluctuating; though the fluctuation mentioned if correct is not going to cause issues for these fish.  Most aquaria will settle into a biological system that maintains stable (or relative stable) pH.  My seven tanks have done this, and the pH is variable among them,  Some are in the low 5's or lower, others remain around 6.2 to 6.4, depending upon fish load and plant species.  However, your platy are livebearers, and these need some mineral in the water or they can develop internal health issues and usually a much shorter lifespan results.  The GH is more important, but pH for these fish should be above 7.
 
I won't use Excel, as I've explained.  It is not necessary, and I see it as a serious risk.  Just to illustrate, photos below are two of my planted tanks, with no added CO2 in any form, and the fertilizers previously mentioned.
 
Byron.

Thanks! That is some really good information!