Crushed coral or playsand

[jacquesb]

Hi Dane -

Unfortunately I am relatively lazy, and unfit. So - for me to collect 40kg's of sea/beach sand, would be a HUGE effort.

So - going to the local Builder's Warehouse, and asking them to load 2 x 20kg bags of playsand, was far easier.

No other reason.....

Valid point :razz:

agree that natural sand is inert - was offering it as an alternative to playsand. The grains are round, offering better surface area etc.

As an aside Jacques - why did you choose playsand instead of beach sand? Is it much whiter? Just aesthetic preference?

thnx
Dane

 

[riyadhessa]

Hello bra...If i am you don't use play sand....To clean it is a mission lol...

If you want i can take you a spot whr i got my sea sand...Everyone say yer it give s a dull look, i think they should swallow thr words...My new system's substrate is just sea-sand...And its looks kewl...PM me and can go together as i need more lol

 

[Nemos Janitor]

JB One must not get the impression that the aragonite or Calcium carbonate substrate dissolves at pace. The PH really has to drop for this to happen. One cannot use the substrate to provide buffering and a calcium source for the coral.

Apart from all the scientific blab I can assure you that in our experience we see better results with aquariums that have either an aragonite or AM hydrocarbonate substrate of about 30 - 50 mm. When i say results i mean maintain stable PH, KH, Ca and Mg. I am not talking about SPS and high calcium consumption tanks only. Take the tank example in the coralline algae thread. No Calcium is dosed. The only source of calcium to produce the coralline could come from the Tropic Marine Pro Reef salt or the AM hydrocarbonate substrate. Considering that this tank only has a 100l a month water change (just over 10%) it is unlikely that all of that coralline was produced by the calcium in the salt. IMO it is drawing the calcium from the substrate.

SPS, LPS and high calcium consumption tanks still have to be dosed the necessary calcium to accommodate the coral uptake.

Getting back to the original question as to whether Crushed coral or play sand is better. I would say play sand. But would go with Aragonite first followed by the hydrocarbonate, then the play sand then the crushed coral. With play sand and cruched coral i find one has to work so much harder on water parameter stability than on aragonite or hydrocarbonat. Of course you guys at the coast have other options which i have no experience with.

 

[jacquesb]

LOL - no problems Nemo's. I think that I can understand your statement about "better results in tanks where there is only aragonite". That I cannot contest at all.

 

[Nemos Janitor]

JB i have some used hydrocarbonate, about 25kgs that was removed from a tank that a client did not like,and wanted courser gravel because it was scratching his acrylic tank. If you can like to try it and can arrange to collect/ship you are welcome.

 

[jacquesb]

Many thanks Nemo's. Let's see how I can get that here in Cape Town. I will get back to you on that. I really appreciate the offer.

 

[deadmeat2016]

Ph

I 3rd year geology at stellenbosch and u guys are confusing me a bit here, firstly aragonite(which is a mineral) is a form of calcium carbonate, in fact the most soluble, re-read my first post, the solubility and dissassociation constant for aragonite is Ph dependant and dependant on the concentration of Ca+2 and CO3-2 ions in the water so in the situation that ion concentrations are low at Ph 8, the arag would dissolve vvveeerrryyy slow, thousands to millions of years , think calcium reactor, we inject CO2 into the water which gets the ph down to about 6.8 changing solubility of calcium so that it is at max concentration in the reactor, about 680ppm - it is in equilibrium regarding the Ph -CO2 can only be present at a certain pressure so Ph is always about 6.8. Bit of a mouthful hope it helps

 

[deadmeat2016]

Oh and yes silica is inert, dissolves at very low Ph(<1), look up hydrofluric acid - one of the only things tht dissolves silica, nasty stuff

 

[jacquesb]

I 3rd year geology at stellenbosch and u guys are confusing me a bit here, firstly aragonite(which is a mineral) is a form of calcium carbonate, in fact the most soluble, re-read my first post, the solubility and dissassociation constant for aragonite is Ph dependant and dependant on the concentration of Ca+2 and CO3-2 ions in the water so in the situation that ion concentrations are low at Ph 8, the arag would dissolve vvveeerrryyy slow, thousands to millions of years , think calcium reactor, we inject CO2 into the water which gets the ph down to about 6.8 changing solubility of calcium so that it is at max concentration in the reactor, about 680ppm - it is in equilibrium regarding the Ph -CO2 can only be present at a certain pressure so Ph is always about 6.8. Bit of a mouthful hope it helps

LOL - Deadmeat! That is awesome information, and yes. Exactly. I am not TOO sure why you are getting confused?