DIY base rock...a la Garf

well, the fishies are still happy this morning, and the crabs have started climbing on the rocks, so things are going well...

 

WEEEEEEEEELLLLLLLLLL.....I finally got some cement and sand :mrgreen:

I picked up 2 bags of play sand from Home Depot. Should that be ok to form the rocks in? Or does it have to be the sand we use for the tank for safety reasons? I would hope that play sand that kids play in are safe enough for making rocks.

I just have to go pick up a bag of rock salt and crushed coral. By the way...what type of rock salt should I get? The kind you use for cooking? I wouldn't think I could use the kind that you salt sidewalks with or the kind you use for water softeners. Who knows what chemicals they have in them! Anyone know?

 

Ask Eddie!

 

Project, congrats on the rocks. I think it will look great when you load that tank up. Especially if you plan on doing more caves and tunnels.

The only kind of rock salt I would avoid is the stuff that has the round, man made stuff in it. I think it is a slower disolving man made grain for melting snow. I just got mine at the animal feed store to be on the safe side. The quality isn't going to make much difference since you have to disolve it all out before adding it to your tank anyways, but I think your right to avoid anything that might have chemicals.

As for the play sand, it is a silica based sand, so I wouldn't use it if you plan on leaning your rocks up against the tank, since it will scratch up the glass. If you they're just gonna be stacked in the center of the tank I think it should be fine. On another note I have heard that silica sand can feed nuisance algea, but I have no idea whether that is true or not.

 

What eddie said. Silica can feed diatoms a nuaicance algea. Plus, if you use argonite(sp?) sand, the rocks will help buffer the pH of the water.

Brian

 

Cool, thanks guys!!! Back to the store it goes.

Don't you think any salt gets trappedin bubbles in the rock, waiting to leach out if the rock breaks/chips off? Like, does the salt dissolve INTO the rock while the rock is hardening? I'd hate to have a whole 125g tank crash from this.

Sorry, just being paranoid

 

as long as you wash it in the ways described earlier in the thread, you will be fine. The water will wash the salt away. Check your salinity regularly if you are concerned about it. You really should be checking it on a regular basis anyways.

 

After you make the rock you soak it for days, draining the water daily. During this process all salt left would dissolve. The rock is very porous, partially because of the little pieces of salt that were in there when you make it. I'm assuming that's why you use salt in the first place, to get all those porous little holes. Is that right Eddie? :question:

 

The point of the salt is to hold the space empty of concrete so that when the salt dissolves, you get an open space, hence making the rock porous. It's just like the way the used to make pool decking.

 

+1 to those above.

 

yea, i would stay away from the silica based sand.. and the water bath cureing process does a couple things for you, one it helps leach out the lime thats in the concrete, (lime will make your ph go up) and the salt is what makes the holes and surface texture.

one thing that i noticed when i was doing the water cureing on my rocks is that if i broke a peice off, it was pretty obvious that the salt insde took a lot longer to dissolve than i thougt it would.. but after about 2 months of it soaking, i couldnt detect any serious concentration of salt in the soak water, thats when i decided it was safe...

Then one other thing that i have noticed is that my tank looks and is acting like it had a mini cycle, cause i have a little of that red slimy stuff comming back. I think thats probably mostely from me stirring up the tank so much when i put the rocks in, cause i totally re-arranged everything, including most of the sand, so, i think i disturbed the balance... now i'm watching and waiting to see what happens...

but all my fishies are still alive and have a good appetitie, so i'm not too worried yet.

 

Yeah, that was really my main concern, was what if I did a 8-10 week soak, my salinity was 0 and PH stabilized, then a piece breaks off in the tank...if some of the salt that is in one of the sealed cavities gets broken open, would it affect my tank's salinity. I understand that the salt makes the rock porous, so yay, but just that "what if" scenario Again, just me being paranoid. You invest so much time and money in your tank, that you really try to be careful what you put in.

Good news is that after much searching, I finally found a livestock feed store near me. I'll be picking up a bag of crushed oysters. then I'll swing by the lfs and get a big bag of aragonite sand, then I'll return the play sand to home depot (the kids were eyeing it....I quickly nixed their sandbox idea....then again...........maybe we will make them one out back.)

 

I am anxious to see you guys finished product!

 

come on sand boxes are fun i hauled 6 truck loads of sand for the kids sand box i built. the only bad part is that the kids wont leave the sand in it its in the house in the yard every were but were it is suppost to be

 

I agree with the 6-8 weeks soaking time, when I first made the DIY rock video I had not fully cured the first rocks. So the longer you can cure the cement, and disolve the salt the better. Once the salinity levels in the water are at of very near 0, then it will be safe. I wouldn't worry about the salt on the inside of the rock, because these rocks are super porous.

On another note I have some bad news about my rock ... My landord caught wind of my aquarium activities, and has expressly prohibited an aquarium (I totally understand where she is coming from). It looks like I'm going to have to wait until I have a house of my own before I can continue

 

With all your planning and work, that's too bad Eddie! Down with landlords!:grumble:

 

that sucks. sorry to hear about your setback

 

yea, i water soaked mine for over 2 months i think, i'd have to go back and find the post where i said that i poured them.. but anyway.. after around 2 months of freshwater soaking, the water being automatically changed in the bucket every 6 hours, my rocks are IN MY TANK! have been for a few days now.. and everything seems to be going well so far... pics are above in this thread...

oh and i did break a spot on one of the rocks, and there wasnt any salt inside the spot that i broke... further more, its rock salt, not the powdery stuff that we use to make our salt water, so its gonna melt really really slow, so if you just watch your tank's salt levels over the course of a couple weeks after putting them in the tank, you'r gonna know if theres an issue or not, and if you do see your salt levels rising,(more than what evap causes) then just do a water change with the new water just a tad less salty than what you normally mix... that will help compensate some for it.. but if you water cure them for 2 months like i did, i doubt you'll have any problems.. like i said, mine are in the tank and everyone seems happy...

 

Lame! I'd move. If it wasnt in the lease, then she can't enforce it. I'm not saying that you should go ahead with the aquarium anyway, but you should tell her that since she is changing the terms of your lease that you will be moving out and that you expect your deposit back.

 

Great in theory, but not practical most of the time.