Fill PVC anchors for aquascape with sand or water in 6" sandbed?

[spd3001]

I'm building out a 90 gallon reef tank with a deep sandbed. The tank is 36" deep and 24" square. I plan on keeping a yellow-headed jawfish and likely a goby/shrimp pair. They'll be digging up the sand so I want to anchor my aquascape to a PVC skeleton that will be buried beneath the sand. I don't want them to be able to shift the aquascape around. So what should I do, fill the pipes with sand or just leave them open and let them fill as they may? Should they be water-tight and empty and epoxied to the bottom of the tank? Anybody have some related experience they can share? The bed will vary in depth from 5 to 8 inches.

 

[spd3001]

I have a PVC structure for some rocks in my reef. I drilled a bunch of holes in them so they wouldn't capture air, and could have a tiny bit of water movement. I figured like every 6-12" a 1/4" hole was good. The rocks sit on them and hold them down, though they did hold by themselves ok. Basically I put them in first, then put in sand around them, then put rocks on them.

I have had no problems with this setup.

Good to hear, I'll do something similar but, aside from the vertical branch rock, I'm looking at anchoring some small shelf rock separate from the main "tower" for some encrusting corals so they don't take over the branch rock.

 

[spd3001]

Not sure if its too late for you but I used acrylic "stilts" glued to a sheet and put that in first before sand. Here's an extra piece i later pulled out of the tank.

That looks like a great approach. I have a bundle of clear acrylic rod so I'll take a look at that. Maybe avoid the PVC bits all together.

 

[terraincognita]

Thanks for the info. The jawfish is likely to be the first fish in the new build followed by the goby/shrimp pair. Do your's get along well?

My Jawfish will make threats to my Goby if he gets too close when outside of the burrow, but they've never gotten into any real scuffles.

The goby just runs back to his burrow lol.

I've got tons of ample lower rockwork for hiding for both of them though.

horrible photo but just took it 25 seconds ago for some idea

they happened to both be in frame.

not normal lol.

 

[spd3001]

Let’s not get into how much tin will be introduced into water with a bunch of added pvc structure

An Environmental Product Declaration (EPD) for PVC pipe, certified by NSF International, states that: “PVC pipe and fittings are resistant to chemicals generally found in water and sewer systems, preventing any leaching or releases to ground and surface water during the use of the piping system. No known chemicals are released internally into the water system. No known toxicity effects occur in the use of the product.”

NSF/ANSI 61 requires the total of any potentially leachable amounts of tin from PVC pipe be less than the Single Product Allowable Concentration (SPAC) which is set based on the type of organotin. (For the stabilizers used in PVC water pipe, the SPAC is 4μg/L = 4 parts per billion.)

 

[spd3001]

My Jawfish will make threats to my Goby if he gets too close when outside of the burrow, but they've never gotten into any real scuffles.

The goby just runs back to his burrow lol.

I've got tons of ample lower rockwork for hiding for both of them though.

horrible photo but just took it 25 seconds ago for some idea

they happened to both be in frame.

not normal lol.

So cute!

 

[olonmv]

The acrylic rod idea is pretty nifty.

 

[theMeat]

An Environmental Product Declaration (EPD) for PVC pipe, certified by NSF International, states that: “PVC pipe and fittings are resistant to chemicals generally found in water and sewer systems, preventing any leaching or releases to ground and surface water during the use of the piping system. No known chemicals are released internally into the water system. No known toxicity effects occur in the use of the product.”

NSF/ANSI 61 requires the total of any potentially leachable amounts of tin from PVC pipe be less than the Single Product Allowable Concentration (SPAC) which is set based on the type of organotin. (For the stabilizers used in PVC water pipe, the SPAC is 4μg/L = 4 parts per billion.)

That’s a good find. I know there is tin in the manufacturing process. As well many hobbyists are finding hi levels of tin with the availability of cheap easy testing these days. As well it’s dif when water travels through a pipe, as compared to siting in the same saltwater with many trace elements. Hope you’re right

 

[Saltyreef]

An Environmental Product Declaration (EPD) for PVC pipe, certified by NSF International, states that: “PVC pipe and fittings are resistant to chemicals generally found in water and sewer systems, preventing any leaching or releases to ground and surface water during the use of the piping system. No known chemicals are released internally into the water system. No known toxicity effects occur in the use of the product.”

NSF/ANSI 61 requires the total of any potentially leachable amounts of tin from PVC pipe be less than the Single Product Allowable Concentration (SPAC) which is set based on the type of organotin. (For the stabilizers used in PVC water pipe, the SPAC is 4μg/L = 4 parts per billion.)

Good info.
This is my ICP analysis of a 5 year old reef using sch. 40 pvc.
No elevated tin or any other minor elements or pollutants

 

[Saltyreef]

That’s a good find. I know there is tin in the manufacturing process. As well many hobbyists are finding hi levels of tin with the availability of cheap easy testing these days. As well it’s dif when water travels through a pipe, as compared to siting in the same saltwater with many trace elements. Hope you’re right

You're not 100% wrong.
I know Its been banned in a number of countries for being toxic and releasing carcinogens.
Heavy metals such as lead and cadmium.....
But atleast in the pipe thats on my system, its not leaching anything yet per ICP.
They could have changed something in the manufactuering process i dunno... (have you seen that tan/brown pvc they use in south america?)
Or give it 10 more years until the pvc starts breaking down.....lol

 

[theMeat]

You're not 100% wrong.
I know Its been banned in a number of countries for being toxic and releasing carcinogens.
Heavy metals such as lead and cadmium.....
But atleast in the pipe thats on my system, its not leaching anything yet per ICP.
They could have changed something in the manufactuering process i dunno... (have you seen that tan/brown pvc they use in south america?)
Or give it 10 more years until the pvc starts breaking down.....lol

The manufacturing process has changed a couple of times over the years. In late 70s, and late 90s. Maybe more, idk. The process was changed for the better (less leaching).
Pvc leaches most when new. As the compounds leach the pvc becomes more brittle. Uv is not good for pvc.
Tan pvc is cpvc. It tolerates contaminants better, like chloride, and is rated for higher temps. It’s also thinner so you’d need cpvc fitting to instal. It’s not new and is not only used in South America. Never really took off here and with pex widely available and approved for most applications now, cpvc is loosing popularity.