Sand bed turned to concrete!!

[lou dog420]

What caused this??

 

[Labridaedicted]

What's your ph and dosing schedule look like? This is usually due to carbonate precipitate binding to the substrate

 

[DLHDesign]

Are you dosing anything for Alk? If so; how much for what size tank and with what in it?

Over-dosing Alk can cause it to precipitate out. One way this can manifest is that sand can bind together, causing it to "cake". You would have to have some serious over-dosing going on in order to get it to "concrete" I would think, but this is the only thing close I can think of...

It would likely help if you provided any details you may have on your tank. Size, population, equipment, chemical test levels that you have done, etc.

 

[lou dog420]

I have not tested ph in a long time. I have a home made dripper using Mrs wages.

 

[Labridaedicted]

I have not tested ph in a long time. I have a home made dripper using Mrs wages.

Ok, ph and alk numbers will be necessary to say for sure, but I'd wager high ph has caused carbonate to come out of solution.

 

[lou dog420]

Are you dosing anything for Alk? If so; how much for what size tank and with what in it?

Over-dosing Alk can cause it to precipitate out. One way this can manifest is that sand can bind together, causing it to "cake". You would have to have some serious over-dosing going on in order to get it to "concrete" I would think, but this is the only thing close I can think of...

It would likely help if you provided any details you may have on your tank. Size, population, equipment, chemical test levels that you have done, etc.

Tank is 100 gallon reef thats been running for 9 months. I use a home made dripper with lime water ( Mrs wages pickling lime ). Early on my alk and cal were a little high, 10 dkh and 500 cal. I have dropped my alk down to 8 over the last couple months.

 

[lou dog420]

Ok, ph and alk numbers will be necessary to say for sure, but I'd wager high ph has caused carbonate to come out of solution.

I do have my skimmer intake plumbed outside to fresh air. That combined with kalk maybe made ph too high??

 

[Labridaedicted]

Could be a combo of things. Is the concretion recent? Anything changed recently dosing wise?

 

[lou dog420]

Could be a combo of things. Is the concretion recent? Anything changed recently dosing wise?

No, its been that way for a while. Only thing I've really changed is lowering my alk over the last couple months but it was already concreted before I started.

 

[Labridaedicted]

Yeah, that high alk at the beginning likely caused it. You can probably break it up a bit but sometimes it has to just be replaced if it bothers you. Otherwise, you can just confuse some gobies

 

[McArcher]

Are only dosing the clear liquid of the kalk solution?
Same thing happened to me many years ago. I was dosing the kalk right after mixing before the undissolved powder settled out.

 

[bmacrc]

My substrate has also turned to concrete. I can break it up with some effort. Would that be okay if I could get it back to sand consistency or do I need to remove and start over? Thx, Bob...

 

[vetteguy53081]

Sounds like its been a while for water change. Time to siphon and break it up loose and make it a habit to loosen up and siphon sandbed at 1/3 of tank bi-weekly. 1/3 rd . . meaning left side, next time center and next time right side 1/3 and repeat.

 

[kisember]

I want to turn sand to concrete intentionally with no luck.
I've put different substrates into separate containers for experiment: crushed coral skeleton and ATI Fiji white sand (aragonite afaik). Filled the containers with fresh water and added either acetic acid, kalk (ph ~12, Ca(OH)₂) and Sodium Carbonate (Na₂CO₃, alk part of Randy's recipe, ph ~11)
Storing the substrates in cup covered containers at such low/high ph for about a month and none of them stick together.
Any ides how could I achive to stick them together using reef safe solution like in the 'issue' of the OP instead of using glue or cement as adhesive?