Buying a Used Tank

[Europhyllia]

What are some things to consider when buying a used tank?

Does silicone go bad if the tank stands empty for awhile?
If so how long is okay?
About how frequently do tanks need resealing (tank age) even if they held water the whole time?
How expensive is it to have a tank professionally moved?
Is there a site that explains all the RR drilling (like why would I want a hole in the BOTTOM of my tank)?

[StevenSeas]

IME silicone does go bad if the tank stands empty of water for a while. As far as I know there isnt a rule of thumb on the length of time but rather just a simple leak test.

[hobogato]

i dont know that there are difinitive answers for any of those question karin :)

i do know, imo, if you are going to drill a tank, it is safest not to drill the bottom. If any panel on the tank is tempered, it will be the bottom and there is no sure way to tell. if you try to drill tempered glass, it will shatter (ok - not 100% of the time, by 99%+ of the time)

[Europhyllia]

I was actually just looking at a tank that already had the bottom drilled.
This is probably completely DUH but why would you want the hole on the bottom (instead of the sides)

[allan]

And I can say from experience that 100 percent of the tanks I've drilled have resulted in shattered glass (ace, forgot to bring your bit Saturday).

If, or when, I upgrade to the 1,000 gallon tank it will be used as i've not had any bad experiences with the ones I've had.

[allan]

mine are on the bottom and the pipes stretch all the way to the top. Must be a reason for this although it does seem like a waste of space.

[hobogato]

the traditional way to do a reef ready tank was to drill drain and return holes in the bottom and use an internal overflow box to hide them. the method of drilling the sides is credited to anthony calfo - hence a calfo overflow on the back or side of the tank. however, nearly all of the "calfo" overflows you see now are modified versions. the original that calfo designed was glass and spanned the entire back of the tank to increase the length of the edge the water spills over which makes a thin layer of spillover (where wastes and protein are the most concentrated). for a true calfo system, minimal surface disruption is also required to allow the proteins and waste to concentrate in that thin layer of spillover water so they can be taken to the filtration and removed.

[StevenSeas]

I think another reason RR tanks are drilled on bottom is so that the piping can be straight which allows for greater gph capacity of both the drain and return. might not be why its done but just a nice side effect

[Europhyllia]

Thanks! Now it also makes sense why the overflow boxes in reef ready tanks go all the way to the bottom.

[Europhyllia]

I think another reason RR tanks are drilled on bottom is so that the piping can be straight which allows for greater gph capacity of both the drain and return. might not be why its done but just a nice side effect
So what does a return look like on an RR tank? The water from the sump enters through the bottom of the display tank and then what?

[hobogato]

it goes up and over the top of the overflow and then bends into the tank. some overflows have a notch so it is even with the top of the water.

[StevenSeas]

traditionally goes straight up to the top of the tank and then either exits there via an elbow, ball and socket tubing, or a T and then ball and socket tubing. Thats just with all the tanks I have dealt with, some run a little diffrent but thats the way manufactures do it and how i have seen a lot of DIY done. on my girlfriends 75 that I got complete control over (for the setup only) I ran the return to a manifold (basically closed loop but from the sump) so that there is soo much surface disturbance that at times her T5s give a slight shimmering effect lol. Mind you thats all from a mag9.5 w/ 6 outlets so thats like 100-150 gph per outlet. nothing fast but makes it so both her koralias can be used deeper down and not worry bout the surface.

[Neptune@gabesfish]

In most cases temp bottoms are only on some of the smaller tanks like 100gal and smaller.. like i said in most cases. when draining from bottom it is a preasure drain so you can push more water through it without worry of flood.. on back wall it is a slower drain.

as far as moving a tank it all depends on size,plumbing,livestock..but on average I charge $75 an hour and $50 an hour per person that is needed to move tank. so normally about $125 an hour

[Europhyllia]

it goes up and over the top of the overflow and then bends into the tank. some overflows have a notch so it is even with the top of the water.
so intake and outlet holes are side by side and hidden in the long overflow box

[Europhyllia]

as far as moving a tank it all depends on size,plumbing,livestock..but on average I charge $75 an hour and $50 an hour per person that is needed to move tank. so normally about $125 an hour
definitely something to consider when budgeting for this. I bet for my kind of tnak it would be closer to 4 people and 2 hours to get it out to LaVernia...:hypnotyized:

[Neptune@gabesfish]

yup both pipes side by side

[hobogato]

[edit - darnit, you beat me to it gabe]

yep, that is usually the way it is done. if there are multiple overflow boxes, usually each one has a hole for drain and a hole for ruturn.


so intake and outlet holes are side by side and hidden in the long overflow box

[Europhyllia]

so the advantage to having two overflow boxes on the back over 1 overflow box on the side is better (more even) waster removal?

[Neptune@gabesfish]

At the same time Karin it depends that price is only for a live tank.. If we are moving a dry tank that has already been torn down and it is ready to pick up and go we dont charge nearly as much .. In this case we normally come to a agreed price with customer ..most of your expense would be that it has to be taken to La vernia..

[StevenSeas]

so the advantage to having two overflow boxes on the back over 1 overflow box on the side is better (more even) waster removal?

This is my opinion yes, however with enough flow (and in the right direction) one overflow on the side with the same amount of drains and return as 2 on the back on the side can be rectified

[Europhyllia]

At the same time Karin it depends that price is only for a live tank.. If we are moving a dry tank that has already been torn down and it is ready to pick up and go we dont charge nearly as much .. In this case we normally come to a agreed price with customer ..most of your expense would be that it has to be taken to La vernia..

:D excellent. Just gotta save up for the tank and then I can have it moved in the next time DH is TDY... ;)