Concrete

Discussion in 'Anything DIY Related' started by Ross, 27 Jan 2010.

  1. Ross

    Ross

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    Hey Guys

    Starting my Aquascaping (with very little luck so far) and want to build a few bases for rock. I assume concrete would be the best.

    Do I need anything special, or any precautions I must take?

    Ta,

    ROss
     
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  3. durleo

    durleo

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    I think the guys use white cement cos it has less impurities and you can use 3 parts sand and 1 part cement - you can add crushed coral to make it more realistic and also pool salt in the mixture. When ur complete structure is done you soak the complete thing in a r.o and the salt should disolve and leave the rock porous. I think you got to soak it for like 3 months though so that it doesnt affect the PH.
     
  4. dallasg

    dallasg Moderator MASA Contributor

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    also leaving the rock in slighly salty water for 30 days to cure and leach all the bad stuff out.

    i made rock, and left it in a bucket with RO and dishwasher salt, about a cup per 100Lfor 20 days, then i put them in with just RO water for another ten, then change the water and test a day later to see if there are nitrates or phosphates
     
  5. dallasg

    dallasg Moderator MASA Contributor

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    if you search GARF.org website there is a article on making rock and a video
     
  6. jacquesb

    jacquesb Retired Moderator

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    Very nice idea Ross. Also look at Simon Garrett's thread on UltimateReef.net.... he made his own "coral bommies" from white cement. Great ideas.

    Also - DON'T USE METAL in the rock (to try and strengthen it - I know - it might be logical - BUT, just in case).... ;)
     
  7. dallasg

    dallasg Moderator MASA Contributor

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    i agree with jacquesb, no metal, what one can use are the plastic rods used at ballon holders, make a good substitute as Robar
     
  8. durleo

    durleo

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    Maybe you could use 20mm electrical conduit and it is bendable - I want to do a pillar type rock structure with the pvc pipe in it like a closed loop - so that the flow in the tank will be more random
     
  9. Ross

    Ross Thread Starter

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    Thanks guys, the question now is where to get white cement.

    Also 3 months to cure, that is hectic, I want to fill my tank and start the cyle next weekend... he he. (Don't say be patient, I have been waiting over a year to sort this baby ;) )
     
  10. durleo

    durleo

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    I guess you can cure it a bit quicker - maybe use a power head and change the water more often - You can let ur tank cycle without the rock because it will not have any life on it to die so it should not cause a spike in ammonia and nitrate. When the rock stabilises then you can add it to ur tank.
     
  11. shane

    shane

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    Hi Guys,My question is , what is white cement and where do you get it?I have not seen white cement anywhere. Is it called something else?Cheers
     
  12. Ross

    Ross Thread Starter

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    That would be fine, problem is I don't want to make rock, I want to build a bas for my rock around my CL..... mmm, will figure something out.
     
  13. leslie hempel

    leslie hempel Moderator MASA Contributor

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    white cement can be found at most pool places, i found that a 30/40kg bag was around R350..

    i for precautionary purposes would asvise a short curing period, but i have put weathered concrete blocks into tanks before and added fish as soon as the cycle was complete with no ill effect, in some cases as soon as 2 weeks after but with LR being in the tank from day 1....
     
  14. jacquesb

    jacquesb Retired Moderator

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    Guys - go to any Builder's Warehouse or Build-IT, etc..... ask them for White Cement. It usually comes in smaller bags. And it is indeed more expensive that "normal" (grey) cement.

    Personally, if you are not in a hurry, you should be able to place the "uncured" rock-work/base, into the tank while the tank is cycling. You tank might just cycle for slightly longer..... BUT, in this case, I would definitely suggest doing some water changes during the cycling process. Remember - the cement would push the pH and alkalinity of the water up quite high....

    Ensure that you can measure these.......
     
  15. dallasg

    dallasg Moderator MASA Contributor

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    yip, jacquesb is right, remember to monitor the alk and ph

    also the concrete cures better in water, even try soaking it for 2 days, then rinse and dry, then soak another day, 3 days wont be too long.

    remember we also want this rock to be a little porous, so u can add some coarse salt to the mix, then when u soak it the salt will dissolve leaving you nice porous stone.
     
  16. Neil H

    Neil H Moderator MASA Contributor

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    guys one thing to remember is that concrete if i remember correctly has compressive strength but lacks tensile strength (not sure if i have the right terms there, but basically cement is stron to stand on, but it is not strong laterally ..... i.e. puch a long beam out over a cliff made only of cement and its weight will soon cause it to fail, stand the same beam vertically and it will hold) in addition to the plastic tubing structure one should also put in a lattice of strengthening agents, such as plastic 1 inch mesh found at builders.... much the same a reebar it will help with lateral strength
     
  17. davidfr7

    davidfr7

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    White cement is also sold in 500g packets
     
  18. Ross

    Ross Thread Starter

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    Thanks for all the input guys, I think I will try this. I am planning on cycling my take for quite a while to make sure it is 100% and to give me time to finish getting things like the computer and stuff. Want it to be completed before i put fish or coral.
     
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