seeding aragocrete-display or bucket?

[rhidien]

About 3 months ago, I made some aragocrete. It's still in the slow process of curing.. I think partly it's taken so long, because I used portland cement, made fairly large pieces and was trying to cure it out in my cold garage. I since brought it inside and am still waiting. It doesn't seem to be leaching out the large amounts of calcium anymore, but the ph is still high...anyway....
When the ph finally goes down, do you think I'd have better results "seeding" the aragocrete in buckets, with a power head, heater and some live rock as opposed to my main display? I have a variety of small hermits in there and have read that their eating/picking greatly slows down the coralline growing process. However, I don't have an extra light to put on the buckets, if I try to go about it that way? Do you think a couple of months with live rock, seeing without a light would be more beneficial, or seeding in the tank with hermits would be? I know the live rock doesn't grow and spread that well without light, but also know it survives without a lot of light, at least for a while... just wondering which was the better idea?

 

[jlehigh]

garf.org has recomendations for stimulating corraline growth ect with agrocrete. I believe they reccomend normal output flourecent bulbs, 1 daylight and 1 actinic.

I made agrocrete table structures to support my Live Rock in my display. I had cured the agrocrete for 4 months prior to it going in the tank. It has now been in the display for 7 months and is JUST now growing corraline.

Point and case: It takes a looooong time for this stuff to grow over and even at that point it's filtration abilities are not so great given the density.. You could end up with your DIY rock in a bucket for a very long time taking up space and electricity. I would put them in the display. I recomend DIY rock be used for asthetics and as a suplpiment to the appropriate amount of LR.

 

[dnjan]

I put mine directly into the tank after curing.

You mention that yours is curing slowly? How often are you changing the curing water?

 

[rhidien]

Been changing it about once a week. The calcium level has dropped, not seeing all that crust on top of the water, but the ph is still real high.
I decided to take all the rock out of water, for at least a few days. Gonna let it dry out some, then start back on the freshwater bath. Don't know if it will actually help any, but if it dries out, perhaps it will help some of the cement to finish setting and then the underwater curing will be closer to being finished? After the two days setting up in the sand when I origionally made the rock, it went straight to water... we'll see if this helps any... probably not, but worth a try..

 

[dnjan]

The cement will be almost completely hydrated - allowing it to dry out won't make any difference with the amount of cement that has reacted.

Drying may help some of the excess calcium in the aragocrete leach to the surface, but it won't be much.

When curing aragocrete (to remove excess calcium), it is best to have continuous water flow. If that is not convenient, I would put an airstone into the curing water. That way, CO2 from the air will combine with CA leaching from the aragocrete, forming calcium carbonate (which will either float on the surface of sink to the bottom). This reduces the CA content of the water so more CA will leach out.

It takes very little CA to significantly increase the pH of plain water (there is basically no buffering system). So only a little CA leaches out of the rock each time you change the water. That is why continous water change is better. For small pieces, that is easy (put them in the toilet tank). But for big pieces, a tub of water and an airstone may be faster than weekly water changes.