how does pH down work? - The Planted Tank Forum
 
LinkBack Thread Tools Display Modes
post #1 of 9 (permalink) Old 01-19-2006, 01:27 PM Thread Starter
Wei
Algae Grower
 
PTrader: (2/100%)
Join Date: Jan 2005
Location: Kansas City, MO
Posts: 120
Send a message via AIM to Wei
how does pH down work?

Current tap is too high and even with injected co2 im only able to get it down to about 7.6. Im looking for a way to lower my pH and ran across pH down. Does it have any ill effect I should know about?
Wei is offline  
Sponsored Links
Advertisement
 
post #2 of 9 (permalink) Old 01-19-2006, 03:16 PM
Planted Tank Enthusiast
 
KevinC's Avatar
 
PTrader: (6/100%)
Join Date: May 2004
Location: Oshkosh, WI
Posts: 738
If you get a high enough CO2 level (depends on KH as well as pH), you don't need to use a pH down product. However:

I'm not sure if you are referring to one particular product, so I'll talk about reducing pH in general:

Some pH down products use phosphoric acid (H3PO4) or monobasic sodium phosphate (NaH2PO4). Both are acidic (pH<7) and will lower your pH. The problem is the resulting phosphate available for algae growth. The acid reacts with bicarbonate and carbonate ions in the water, ultimately producing water, CO2, and phosphate.

Other pH down products use a dilute mineral acid solution (HCl or H2SO4). The resulting chloride and sulfate ions will not cause a problem in the tank. Here the acid also reacts with bicarbonate and carbonate ions, producing water, CO2, and the chloride or sulfate ions.

One other warning though: these products work by destroying some of your bicarbonate buffering (KH). If you are injecting CO2 as well, you could end up with a pH crash. Also, be sure to re-measure KH after using these products BEFORE you turn the CO2 on.

Kevin

Kevin

72g bowfront planted, CO2, 4x - T5HO, Eheim 2213 and 2217, 2 angels, pristella tetras, blue tetras, betta, albino bristlenose pleco, albino cories. Sword, vals, hygros, ludwigias, java moss and fern, anubias

2g Mac-quarium. Clown gravel, fluorescent plastic plants, and 2 guppies.
KevinC is offline  
post #3 of 9 (permalink) Old 01-19-2006, 05:35 PM
 
PTrader: (0/0%)
Join Date: Nov 2003
Posts: 2,165
DO NOT USE PH DOWN!

this is a temporary chemical 'fix' that won't last long at all. Best way to lower pH is to use CO2 injection, or cut your tap water with RO water.

Why do you think pH down is a solution? and why do you think your pH is too high? 7.6 is a fine pH for 99% of fish out there. If CO2 injection won't lower it, pH down might, but it won't increase your CO2 levels. As soon as you start adding acids or artificial buffers to the water, the pH/Kh chart goes out the window because the chemistry isn't natural anymore.
malkore is offline  
 
post #4 of 9 (permalink) Old 01-19-2006, 07:25 PM
Wannabe Guru
 
Hypancistrus's Avatar
 
PTrader: (0/0%)
Join Date: Oct 2004
Location: West Michigan
Posts: 1,032
If your tap has a high pH due to a high kH, then Seachem Acid Buffer will lower the kH and therefore the pH. It will not invalidate the CO2 chart.

I don't know what is in pH Down, so I can't recommend it.
Hypancistrus is offline  
post #5 of 9 (permalink) Old 01-19-2006, 07:35 PM
Planted Tank Guru
 
DarkCobra's Avatar
 
PTrader: (5/100%)
Join Date: Jun 2004
Location: Baton Rouge, LA
Posts: 3,350
I have used a pH Down product in the past before I started CO2 supplementation, and I can tell you that it was pure algae in a bottle.

It was phosphate-based, but it didn't say that on the bottle. Only in very fine print, "Not for use in planted aquaria." It didn't go into the gory details of why: "...because it will smother your plants in algae!"

Don't use a pH reducer unless you're *certain* it's not phosphate based. Hydrochloric and sulphuric acid based products are fine. Common pool hydrochloric (muriatic) works and is $6 for a lifetime supply, but you have to dilute heavily it prior to use. It's far too dangerous to handle in the original concentration. Be careful doing that.

But if your water has such a high KH that you need a pH reducer in addition to CO2, you may want to look into using distilled or RO water instead.
DarkCobra is offline  
post #6 of 9 (permalink) Old 01-19-2006, 07:49 PM
Planted Tank Guru
 
tazcrash69's Avatar
 
PTrader: (22/100%)
Join Date: Sep 2005
Location: Hawthorne, NJ
Posts: 3,207
If you need to lower your pH, you could supplement tap with RO water.
It's a lot more natural that pH down.

Walter

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
and
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
or my
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
.
Proud former member of:

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


--May the floor under your tank always be dry, and your glass clear!!!
tazcrash69 is offline  
post #7 of 9 (permalink) Old 01-19-2006, 08:22 PM
Wannabe Guru
 
TAF CAF's Avatar
 
PTrader: (12/100%)
Join Date: Jan 2006
Location: Bailey, Colorado
Posts: 1,176
I have used PH DOWN several times, as my water is very high pH and I prefer to keep 7.0 (for breeding and sensitive fish). I have found that using it causes no imediate ill effects, but for long after I have hell with keeping the pH balanced.

I try to use distilled water from the store pre mixed with my tap water to more naturally lower the pH.

Something so expensive and addictive HAS to be illegal. I'm just waiting for the police to break down my door and confinscate my fish food.
What's my sign? I'm an aquarist. --- 18g Planted Guppies, 15g Planted Killifish, 40g Planted Molly, 55g Asst Cichlids, 120g Planted Community, 60g Salty Reef, 180g Planted Goldfish


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
___
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
___
TAF CAF is offline  
post #8 of 9 (permalink) Old 01-20-2006, 12:12 AM Thread Starter
Wei
Algae Grower
 
PTrader: (2/100%)
Join Date: Jan 2005
Location: Kansas City, MO
Posts: 120
Send a message via AIM to Wei
thanks guys I think I will take ur advice and stay away form it and just slow bump up my co2 injection til I get the right pH.
Wei is offline  
post #9 of 9 (permalink) Old 01-20-2006, 05:51 PM
 
PTrader: (0/0%)
Join Date: Nov 2003
Posts: 2,165
One thing to note: if you're lowering pH to get fish to breed, CO2 may not work at all to induce spawning.
Fish 'feel' both the pH and the hardness of the water. It seems that its really the hardness that induces spawning not pH alone.
malkore is offline  
Reply

Tags
None

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the The Planted Tank Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome