Hi all. This is my first post asking a question and just want to say I love the info available while lurking. I moved to a differant state about two years ago and after settling in I set up my wifes 30 gal. to make our home feel right. We also have a 55 long we've held up on setting up after having some issues with the 30. Our problem was heavy PH swings after water changes (we did a fishless cycle). The only fish that has made it over the last few years is a silver dollar thats now about 4". I'm useing conditioned tap water (no RO/DI) for wc and out of the tap the PH is at 7.0. After about two days the PH falls off the scale and reads 6. I originally tried API PH up but it was more or less a band aid and within 3 to 4 days it would drop to 6 again. Our LFS suggested water changes and substrate vacuming but that was already part of our weekly maintenance. I read on here about buffering with crushed coral so I thought I'd give it a try since I really don't like the idea of using chemicals. We now have a rock steady PH reading of 7.8. We've since slowly started adding a fish or two to "test the waters" (rubber lip pleco and dwarf gourami) and all are doing great, the silver dollar is more active than ever. Sorry for the ramble but my questions are does the amount of coral used have have any relation to PH level ( I'm not shooting for a specific number, just curious). Second does the coral in use "expire" and loose its buffering ability over time? My water parameters are 0 amonia, 0 nitrite, 10 nitrate and 7.8 ph. If my GH and KH are needed I'll do a quick test and give results.
PH buffering with crushed coral
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I use florida crushed coral with aragonite from petsmart. I fill up 2 4x8 inch mesh bags for my 210 and I get a steady reading of 7. It does dissolve that is how it buffers the water I believe. So yes you need to add more as it dissolves. My friend used 10 lbs and it never goes over 7.2 from what he tells me.
I'm surprised at how high your pH went. I also use crushed coral and it usually reads around 7.2. Perhaps your coral was 'dusty' and reacted more strongly? Congrats on the more stable pH! Yes, you will want to check the tank's pH weekly before water changes to be sure the coral is still working. The way it tends to drop as it fades is like this: Everything has been fine for a few months, then one week you notice the pH is only 7.1. Then, the next week, it's like 6.8. So if you notice it start to drop, get fresh coral in there asap. Best of luck!
Thanks for the input. I was also surprised at the increase in PH readings, it was literally within 24 hours. I always test before my water changes to see where I'm at. After thinking about it I thought maybe it's not so unusual, look at salt water set ups which are in the lower 8's. I'm assuming this is because they use aragonite and or crushed coral as substrate. I'm only useing one 2" x 8" mesh bag. Then again maybe it has to do with the condition of my tap water. I don't really understand the relationship of GH and KH, maybe someone could skool me. I have the test kits so I'd be happy to give my tap and tank readings if it helps explain. Like I said before I'm not trying to hit a specific number, I'm just trying to understand. I'm just happy I finally have a steady reading.
Coral has a PH of around 8.2... So buffering to 7.8 isnt odd at all
　
This means if you use a ton of Coral it will raise the PH of the water to 8.2 and stabilize.
　
　
If/When practical, test your GH & KH and post them.
　
The GH (General Hardness) isnt critical in regards to PH as GH is a measure of total dissolved solids primarily minerals
　
KH is Carbonate Hardness and is in direct relation to PH. The higher your KH the more stabile your PH will be. Obviously your tap water has a very low KH
　
　
I think you should put tap water in a clean glass let it sit for 12~24 hours stirring it with a clean inert utensil every hour or so Then test the PH
　
The water can be influenced by gases and sediments in the pipelines which will alter the PH test straight out of the tap. Allowing it to sit in an inert environment will allow that effect to dissipate.
　
The gases or sediments do not change the PH of the water, they cause the PH tests to offer a false reading the PH doesnt change over 12~24 hours in an inert container So whatever the PH reading is 12~24 hours later is actually what the PH reading is right out of the tap.
　
　
As mentioned, coral does (quite slowly) dissolve as it buffers. The more acidic the water is the faster it will dissolve the lower the KH is the faster it will dissolve so chances are your coral will dissolve faster than the typical persons experience
　
This means if you use a ton of Coral it will raise the PH of the water to 8.2 and stabilize.
　
　
If/When practical, test your GH & KH and post them.
　
The GH (General Hardness) isnt critical in regards to PH as GH is a measure of total dissolved solids primarily minerals
　
KH is Carbonate Hardness and is in direct relation to PH. The higher your KH the more stabile your PH will be. Obviously your tap water has a very low KH
　
　
I think you should put tap water in a clean glass let it sit for 12~24 hours stirring it with a clean inert utensil every hour or so Then test the PH
　
The water can be influenced by gases and sediments in the pipelines which will alter the PH test straight out of the tap. Allowing it to sit in an inert environment will allow that effect to dissipate.
　
The gases or sediments do not change the PH of the water, they cause the PH tests to offer a false reading the PH doesnt change over 12~24 hours in an inert container So whatever the PH reading is 12~24 hours later is actually what the PH reading is right out of the tap.
　
　
As mentioned, coral does (quite slowly) dissolve as it buffers. The more acidic the water is the faster it will dissolve the lower the KH is the faster it will dissolve so chances are your coral will dissolve faster than the typical persons experience
Thanks for the info nc_nutcase, thats the type of info I was looking for. What you said about allowing offgassing and sediment seperation for true tap testing sounds familiar for some reason. I'll put some in a container tonight and post test results tomorrow after work. I work in the commercial and industrial pump industry and have seen in the area I'm in now there is extreme build up of what looks like clay sedimant (thick rust colored and flaked) on domestic water booster and transfer pumps. I just got done rebuilding two vertical turbines used to boost water pressure for domestic use. One was municipal that fed off a water tower to supply a small town. The second was part of a booster system to feed the upper floors in a fifty story building in a major city. If you saw them when they were pulled you would not want to drink the water any more. Maybe whatever the build up I see has a relation, I just don't know what it comes from exactly. Tap and tank KH/Gh comming soon.
I use ex-live rock in my tanks and it keeps my pH at 8.2 when I used to have to struggle for 6.0. I have noticed that my rock has become more fragile over time due to the more acidic water. You can literally rub it with your fingers and it comes off like your sanding sheet rock. I prefer this method personally since it works as both decoration and buffering.
Interesting idea with the dead rock nfored. I may try that once I feel comfortable with the water conditions on our other tank. I prefer natural deco anyways but my wife is a differant story.
So here are my test results for GH,KH and PH from both tank and tap after letting the tap water offgas and settle for about 20 hrs.
Tap water:
GH: 2 dGH or 35.8 ppm
KH: 1 dKH or 17.9 ppm
PH: 6.5
Tank Water:
GH: 6 dGH or 107.4 ppm
KH: 4 dKH or 71.6 ppm
PH: 7.8
From what was said it looks like the tap water has low buffering due to a low KH and once it has off gassed I'm starting off more acidic than I thought. Am I understanding this correctly?
So here are my test results for GH,KH and PH from both tank and tap after letting the tap water offgas and settle for about 20 hrs.
Tap water:
GH: 2 dGH or 35.8 ppm
KH: 1 dKH or 17.9 ppm
PH: 6.5
Tank Water:
GH: 6 dGH or 107.4 ppm
KH: 4 dKH or 71.6 ppm
PH: 7.8
From what was said it looks like the tap water has low buffering due to a low KH and once it has off gassed I'm starting off more acidic than I thought. Am I understanding this correctly?
Not to steal the thread or anything, but i actually just discovered crushed coral about a week ago when i realized my ph was well below the charts. I usually never mess with it, and when i found out it was way below the charts, and water changes weren't fixing my ph i went the crushed coral route. it fixed my ph pretty quick, but my ph is still steadily rising, and is now reaching about a 7.6, which is the highest my ph reading goes, i took out the majority of the crushed coral, and am doing a water change, i guess my question is how much crushed coral should be in a ten gallon? its pretty "dusty" i guess because i washed all the coral i was going to use in a sock really well and my water got extrodinarily cloudy the first day i put it in.
No worries carsona246, I hope yoou find your answer here. Remember that smaller tanks are prone to large swings in all parameters because of the low water volume. I can only guess the cloudy water was from dust still on the coral.