Switching Gravel for Sand

[markstrimaran]

PH can bounce from 7.5 to 7.8 with daily plant respiration. Added co2 lowers PH.
If your tap is 7.5 ph, and argonite sand is 8.4. Just add 1 table spoon per 30 gallons every 8 hours. Of arm and hammer, calcium carbonate. After a couple of days you will be at 8.4 ph.
If you dumped the entire 16oz box in, your ph will still only increase, too the max ph of 8.4. It would just greatly increase the buffering capacity.

I use saint peters sand, it is a very fine sediment sand found near coal deposits. Mostly quartz. Very round smooth grains. Will not scratch glass with mag scrapper. It has not caused any pump problems.

I hold ph at 7.8with two TBS spoons per week. With 155 gallon tank vole.

 

[Narwhal]

How does adding dry reef rock and limestone effect the ph when put in?

 

[markstrimaran]

It all depends on the surface area that is available to be dissolved. A pound of 1/8" crushed limestone. Will buffer more than a solid one pound rock.

An ounce of 75% yielding solid calcium carbonate limestone, will take a while to disolve.
An ounce of pure powdered calcium carbonate, will disolve instantly at 7ph.

With a minimal bio load the solid rock will probably hold the pH steady. As the bio load increases. It will hit a point were fish waste acid build up equal the limestone ability to buffer.