Water buffering with Sand grit/Crushed coral?

[Klawz]

After experiencing my PH lowering progressively over time ive decided to try using Crushed Coral/Sand grit as a PH buffer. The idea came from looking back through the water chemistry section of this site at most of the posts relating to low PH and this seems to be the most popular advice. The advice also says a handfull or two in the filter should be sufficient. There are still a couple of things im not clear on being

How long will it take for the Coral to take effect and reach its peak (24hrs 3 days etc)?? Dont want to add extra coral and raise it to high.

How long will the coral continue to work for?

At this point its two small handfulls in a stocking inside the filter in a 220litre aquarium with PH well below 6. My old tester (which i just ran out of) tested to 4.5Ph but the API tester i replaced it with only goes to 6PH. Before it ran out the old Tester said it was as low as 5PH, maybe a little under. Mind you ive also read this PH would be fine or even ideal but i felt that the fish didnt seem as happy and im also scared of a PH crash.

Any advice, ideas or experiences would be greatly appreciated.

Thanks

[Hooked]

Hi Klawz,

I'll be interested to see how you go with the crushed coral. I too have had problems with lowering ph, which I have been sorting by adding some bicarb to my change barrels. I too had heard of the adding of the coral but never got around to working out how much to add.
You may have already worked out why your ph is lowering but thought I'd let you know about my recent experience in case it may help you or others out. Also Ph 5.0 may be ok for a tank that's having large water changes and very often but for someone doing the weekly change the info may make them rethink to a higher ph.
It was Merrilyn who mentioned it years ago and it always stuck in the back of my mind. The following is an answer I received from "Regani", a member on the aquarium life forum, to a question I asked about the effects of low ph on nitrifying bacteria.

"Quote" I found an article describing the change of rate of ammonia oxidation (to nitrite) under different pH conditions (was easier than I thought....) the article is here:

http://www.sciencedirect.com/science/article/pii/S0043135496003764

the authors did some detailed studies with nitrosomonas bacteria and the rate of conversion at pH 5.5 (the lowest pH they tried) is about 15% of that at pH 7; the optimum for the bacteria was at pH 8.2 . A recent study has shown that nitrosomonas are actually not the most important type of ammonia converting bacteria (thanks unissuh providing that some time in the past. at least I think it was you...) but it is probably safe to assume that they will react reasonably similar... "Unqote"

Basically in the thread I had started the people good enough to answer explained how the bacteria also chew up carbonates in the water when involved in the process of converting ammonia to nitrites and nitrates. By doing this they lower the carbonate hardness of the water which allows the ph to drop due to not being buffered by the falling carbonate levels.
My problem was that I had low carbonate levels to begin with, about 2 on the API chart. My ph was set at 6.0 to begin with. I have two large Eheim 2080 filters and about 20 Discus and a whole bunch of other "clean up crew" adding to the "food" for the bacteria. Over the week my carbonate level would drop, the ph would then drop, this meant less bacterial conversion of ammonia which led to low levels of ammonia appearing at water change time. I keep my ph at 6.5 now along with raised carbonate levels and I don't have any more ammonia probs.
So I'd recommend to all to check your carbonate levels with the appropriate test kit from time to time as its not always something we think about. Thanks to Merrilyn for mentioning it many moons ago as it stuck with me and it really helped me sort out the recent problem.
As the API test kits don't perhaps go as low as we like and can become less accurate with age, I'm going to invest in a "seneye reef" system soon. Its basically a group of accurate sensors connected wirelessly to your computer which give up to the minute levels of the water parameters in your tank along with an integrated PAR, LUX, and Kelvin meter for light levels (good for us planted nuts!). They are used more by the marine gang but it was shown to me by Natale a recent Discus convert over here that has changed from marine and setting up a very large automated high tech Discus tank.
Hope the info may help and I look forward to seeing how you go with the coral,

Cheers

[ILLUSN]

adding crushed coral at 1tablespoon per 100l would be plenty.

your ph lowers because your filter media becomes clogged and dirty, do a NO3 test before a water change and i bet you have levels over 50ppm

give your filter a clean replace the pads and replace 1/3 of the media in 2 months replace another 3rd and in 2 months after that replace the last 3rd

try and clean your filter (replacing the filter wool) every month, clean it with tank water so as to avoid a re-cycle.

[Klawz]

Twenty four hours in and the ph has risen to 6.4 but the kh remains at zero to one. Happy with the results so far but am still curious/concerned that the ph will continue to rise beyond my desired level. Ph of seven or just below would be great.

Still hoping some of u guys might have some experience or insight into all this so please share anything you can.

Hooked,
Thanks for the info and taking the time to share your experience.
The article was informative and insightfull on something I had no idea about. I believed that the biological bacteria existed equally or close to equally across a wide range of the ph scale except for very low at which point it all just died.
Curious though, if your treating your water with the bicarb before it goes in ur tank water what ph is it at and what amount do you use?

[Klawz]

Sorry illusn I was posting as you posted only I was trying on an iPhone with bad reception. I don't have a no3 test kit but am beginning to realise its important. I have recently replaced the white wool in the filter and gave the media a very very vigorous clean not long ago. I at the time took out a few fish from the tank as I was worried I may have cleaned it too well. I actually experienced a small ammonia spike and bacteria bloom in the water but cleared up pretty quick with no ill result.
You say one table spoon to one hundred litres of water, I hope I haven't over done it. The stuff I used is in pieces approx 10mm by 3mm, would the tablespoon theory apply to this or finer stuff?
Also would you know how long I should wait before I decide I need to add or remove the coral to get to the ph level I'm after??

[Hooked]

Hi Klawz,

I adjust my change water barrels down with hydrochloric acid to about 6.5, I then add about a teaspoon of bicarb which raises the ph back up again. I then adjust down with some more acid to get a ph of 6.5 . It raises my Kh about 1.5 points to about 3.
My tank is heavily planted, but I try to keep my nitrate level between about 10 - 20ppm
As illusion mentioned I clean my filters about every 2-3 months. Alternating which one is cleaned each time. I use an industrial filter cloth instead of the white disposable type in the top of my filters. I get the offcuts from work. Its usually used as a prefilter cloth on industrial air intakes etc. Its brand name is Viledon. I would say it has the same density as a new piece of the Eheim stuff but it retains its shape and density and can be washed over and over. It looks identical to new Eheim cloth. Its a good way to save a few bucks. I use the P15/35OS which has a thickness of half an inch. Here's a link if you are interested,

http://www.freudenberg-filter.com/fileadmin/templates/US_downloads/pad_p15.pdf

Good on you for asking the question as to how much to use of the crushed coral. I've gotta get some,

Just thought I'd mention that my API test kit became quite innacurate when testing for Nitrate after two years and nearly empty. I have a new one now and was surprised to see it was reading about 20ppm lower than it should have when using the old kit. I'll be replacing it every 12 months from now on,

Cheers

[Klawz]

A few days in and it seems I may have over done it with the coral. Ph has risen to 7.2 which is higher then ideal for me. I've now taken the two small handfuls out and left in two tablespoons worth hoping it might stop the ph from rising any more.

A few people asked about low ph and recieved the advice I'm trying. Did no one try this?

[Merrilyn]

I used to keep coral fragments in my filters all the time, but twice weekly water changes kept the pH from rising above 6.5.