saltwater mangroves question

[Bergy]

you will also need an 'overflow' device to drain the water from the tank...

also, do some math and try to figure out how big the sump needs to be and how to build it so it wont overflow when the power goes off...

it is a little bit of math and brain work, but it will pay for itself over and over again or at least you hope it dont

i've got some chaeto and some ulva you can have.. lmk.. :)

I have been looking around (internet and LFS) and I think I am going to "give in" and build a sump.  I found a guy that will build me a glass sump (about 50 gallons) that will "custom" fit under my tank (I have an odd stand that has things to work around).  The custom sump will be about $120-140.  It seems a little high for just a glass tank, but after looking at the hang on the back fuges (that are $140), the sump seems like the way to go.  It will be bigger, and I don't have to build a support to hold up the hang on the back, and, and, and.

So once I have it up and running I will take you up on the chaeto.  The LFS will sell it to me at a "low cost" but from what I have heard, most people have to trim it and just throw it away.  It is something that can just go int a ziplock and mailed? 

[Bergy]

well, corals need stability, so any change is not good/great

1.026 is the average salinity of the reefs of the world where we collect corals, so i doubt that high a salinity poses any problems.

and there really isnt MUCH differnce between 1.021-1.025

that is not significant

but, CALCIUM and ALK is directly proportional to the salinity.. the lower the salinity the lower the calcium, etc

and although you can add/dose calcium to compensate you would be better served having the little bit more salinity in the tank

btw, to correct your solinity just add salt water next time you add water to replace for evaporation...

check the salinity and repeat that process next time you need to TOP OFF

[RandyFolds]

1.026, will that be too high for the fish?  I though any thing over 1.025 would cause the stress. 

Nah...fish are super tolerant, especially if the change is gradual. Most fish can range from a specific gravity of about 1.10 - 1.40 or even higher without any negative effects.

[99trev]

I got a used overflow (for free), Will need a little clean up, and a new "U" pipe/hose, but that should not be too much of a problem.  I have looked at several on utube.

Do the math... is there a formula? Or suggestions? 

From what I have found on the internet, the sump should be about half the size as the main display.  So I have a 120 gallon tank, so shooting for about a 60 gallon sump. As for water space, it depends on how I set up the overflow and where the return pump sits in the sump determines how much water "space" is needed.  If the pump quits, then the sump needs to hold enough until the overflow is not overflowing.  And if the suction of the overflow stops, then the pump in the sump needs to only pump back out so much water into the display tank until it is out of the water (and to purchase a pump that if it runs out of water shuts off).  If there is a formula or ratio or something like that, it sure would be helpful rather than the "trial and error" method that I was thinking about (or dreaming about). 

you will also need an 'overflow' device to drain the water from the tank...

also, do some math and try to figure out how big the sump needs to be and how to build it so it wont overflow when the power goes off...

it is a little bit of math and brain work, but it will pay for itself over and over again or at least you hope it dont

i've got some chaeto and some ulva you can have.. lmk.. :)

I have been looking around (internet and LFS) and I think I am going to "give in" and build a sump.  I found a guy that will build me a glass sump (about 50 gallons) that will "custom" fit under my tank (I have an odd stand that has things to work around).  The custom sump will be about $120-140.  It seems a little high for just a glass tank, but after looking at the hang on the back fuges (that are $140), the sump seems like the way to go.  It will be bigger, and I don't have to build a support to hold up the hang on the back, and, and, and.

So once I have it up and running I will take you up on the chaeto.  The LFS will sell it to me at a "low cost" but from what I have heard, most people have to trim it and just throw it away.  It is something that can just go int a ziplock and mailed? 

[99trev]

Thanks for the suggestion on adding in the salt on topping off.  I was trying to think of the best way to raise it other than during my next water change.  Never thought about adding it little by little with the top off.  That will be a lot easier!

well, corals need stability, so any change is not good/great

1.026 is the average salinity of the reefs of the world where we collect corals, so i doubt that high a salinity poses any problems.

and there really isnt MUCH differnce between 1.021-1.025

that is not significant

but, CALCIUM and ALK is directly proportional to the salinity.. the lower the salinity the lower the calcium, etc

and although you can add/dose calcium to compensate you would be better served having the little bit more salinity in the tank

btw, to correct your solinity just add salt water next time you add water to replace for evaporation...

check the salinity and repeat that process next time you need to TOP OFF

[Just_Greg]

since your tank's outflow is governed by the rate of return from your pump, the O/F will stop siphoning into the sump upon return pump stoppage.  what you're concerned with is BACKSIPHONING, which means that the water in your lines will drain into the sump as well as any water in the DT that will backsiphon into the sump until that siphon is broken, either by the DT level dropping below the returns until they suck air (thus breaking the siphon) or until the water drops below a "siphon break" hole in the return.

as for the necessary amount of space needed in the sump to hold said backsiphon water, you don't really have any math to do.  set up the system, fill the DT, and let the sump fill until the pump is covered (assuming you use a submersible pump).  you can control the water level in the sump by the height of your O/F (external boxes are adjustable).  now turn the system on and see where the level wants to be.  you'll either need to add water to the pump bay if it looks to be going dry or stop the pump and readjust the O/F height, then turn it back on.  once everything seems "happy", stop take a piece of tape and mark that level on your sump.  shut the system off and see if the sump is going to overflow (turn the pump back on if it gets close to the top and readjust by changing the depth of your O/F.

once you're happy, mark the level while the system is running (i just use a sharpie marker).  this is your "fill line".  if you never go past the line, your system will be able to hold the backsiphon water without overflowing.

if your pump is sized (or tuned via a bleed-off valve) to match your O/F rate, the only way for the DT to O/F is is the O/F stops working, but all you need to do is keep the U-tube clear of algae, snails, and air bubbles.  in fact, if you run dual U-tubes, you'll have redundancy.

show us your plumbing or sketch it, and we can help you with your design...

[Bergy]

ok, greg is technically correct in his explanation, but, i had to stop reading after the second sentance... BORING!!!!!

hehehehe


Imagine you are drinking soda.... and the glass is filled to the brim/rim and you suck just enuf to feel the soda on your lip... the glass volume/level will drop, cause there is soda in the straw...If you quit sucking, the soda will flow backwards back into the cup/glass and fill the glass up to hwere it was and it wont overflow...

The problem with our tanks is that it is slightly different then that story above, in that the sucking action, is actually the nozzles that spray the water out into the display tank.. those nozzles are an inch or more below the water surface...

So, lilke greg kinda said, when the power fails or the pump quits working, the water will flow thru the straw, i mean plumbing/tubes/pipes until the water level is at or below the nozzles inside your tank...

You kinda need to figure out how much water that is... you can use math... or you can do it gregs way and hope you dont over flow the sump....(you shouldnt if you start off with really low water level in the sump, as greg said, fill just until the water is above the pump...)

The problem with this method is that by the time you are 'experiemting' and figurin', it is too late.. you already have the sump in place and i doubt anyone would pull it out and relocate baffles...

to figure out how much water will backflow to the sump, you have to figure out how many inches below the water surface the nozzles/inlets are...

lets say 2 inches...

lest say your tank is 36x18..... then you need to do the math to determing how many gallons equals one inch...

there are tank voume calculators all over the place but the math is as follows   (lxwxh)/231

so   36x18x1  = 2.8 gallons  PER INCH

So, you can expect about 5.6 gallons to backflow... I would round up to the next gallon or try to figure out how much water is in the plumbing, and to over estimate to be on the safe side.


this means you need 5-6 gallons of room/space ABOVE the baffle nearest the pump...

you would do the same math... but this time measure from the top of tank to the top of baffle nearest the pump...

This figures that the pump might fail RIGHT AFTER A WATER CHANGE or AFTER A WATER TOP OFF

which would be the worst case scenario... but chances are it willfail after the water level has dropped a bit giving you a little more tolerance...

You can also do some math to figure out the height of the baffles, or the height of the sump, or the size of the 'compartments' to make sure yo uahve enuf room for the skimmer, and a refugium, and figuring out how often you will need to top off...

i.e the bigger the compartment is that the return pump sits in, the more time/days you can go without TOPPING OFF


I have seen some sumps that can not survive a day without top off... so they ABSOLUTELY needed a working/reliable auto top off system...  that or they had to make sure they filled thier sump before going to work each day..

so the quandry is (The goal), to create a big enough RETURN section, while keeping the minimul sized skimmer section, (big enough to fit your skimmer, or maybe your future skimmer), and get a reguium that is big enough to be effective...



also, the baffle placement needs some consideration too.. they have a three baffle system, usually referred to as a OVER UNDER OVER baffle system.. bascilly the water goes OVER the first baffle, then UNDER the second baffle, then OVER the last baffle.. this is to reduce the chance of bubbles being swept thru the sump and back into the display tank...

typically bubbles float to teh top... but if the water flow is too fast, the bubbles can get swept into the current and OVER the baffles...

to minimize the flow/current in the baffles you need to think about white water rafting...

big rivers barely look/feel like they are flowing, when the rivers are big and wide... but when the walls of the canyon get closer the water rushes through them ...so it is with baffles.. if you placed baffles within too small an space, the water will rush throu them, the water level will be a bit higher over the baffles, and the chances of air bubbles and noise is greately increased..

I reccomend at least 1-1/2 inch between baffles... this means 3" of space is 'lost' in baffles, so if you have a 14 inch sump, at least 6" will be for baffles if you ahve THREE COMPARTEMENTs, two sets of baffles...

you can maybe see where space is a premium and math and planning and sketching is vital for a good final product..

anything less then that effort is basic chance that things will be ok...

ok, so my message wasnt much less BORING then gregs... sorry

[cruzincaril]

see trev? i told u these guys were smart...............and funny.........and CRAZY!!!!

[Just_Greg]

dood...who said anything about moving baffles?  the only time i move baffles is if i use "pressure-fit" baffles and i need additional room for equipment in one of the compartments.

or you can do it greg's way and hope you dont overflow the sump

which is why i mentioned if the water gets too high, just plug the pump back in (or use the switch on a power bar), which will put the "backsiphon" water back into the DT.  then re-adjust the O/F and try again (or remove some sump water).   

i suppose some of us have just been "at it" so long that this stuff is second nature to us, altho i DO remember setting up my first sump...i was clueless about the hydraulics of the whole thing.  i knew what a "siphon" was, but that's about it.  i was very proud when it worked just like it was supposed to!

[Bergy]

some folks dont know hwat a syphon is.. i recall going to a guys house to show him.,,,, that was the day that i got the call to go to fraggle reef and help them out of an sos, that ended up backfiring on me. but thats a nother story


as for moving baffles.. no, i dont mean to make it adjustable.. but since he is having a sump made, he can take this oppertunity to design the sump to accomidate the skimmer and fuge and all that..



I would suggest getting the tallest sump you can.. maybe around 18 inches or so, not taller though...


you will gain total safety for the eventual backflow

dood...who said anything about moving baffles?  the only time i move baffles is if i use "pressure-fit" baffles and i need additional room for equipment in one of the compartments.

or you can do it greg's way and hope you dont overflow the sump

which is why i mentioned if the water gets too high, just plug the pump back in (or use the switch on a power bar), which will put the "backsiphon" water back into the DT.  then re-adjust the O/F and try again (or remove some sump water).   

i suppose some of us have just been "at it" so long that this stuff is second nature to us, altho i DO remember setting up my first sump...i was clueless about the hydraulics of the whole thing.  i knew what a "siphon" was, but that's about it.  i was very proud when it worked just like it was supposed to!