how to know water level for top off

[mrpergo]

I was reading Melesreef about sumps and it said to shut everything off let the water drain down back into sump, if there is room left in the return area fill it up.
Turn your pump back on and where the water level is in the return chamber put a mark and that is your max water, and then you top off that area when the water goes below that line.
Is that right ?
I have a 75 gal rectangle with a hob overflow and an Eshopps R-100 sump tank with a Reef Octopus NB-100 skimmer.
What process should I use to find my max water, I've been reading for months and remember reading how to but don't remember where. I know I need to top off in the sump. Just trying to iron out the wrinkles before the residents of the tank get in.....lol
I know I ask a lot of questions but I read a lot which causes me to ask more questions....

[TankStudy]

That is a lot of work turning things on and off. Take a piece of sticker and mark where your water is good at in the sump, usually by the return pump. When water starts evaporating below that sticker, fill RO/DI water back up to that sticker. This is assuming your topping off by hand.

Hope this helps.

[Mark9]

When you shut everything off, the sump should not overflow.
If it does, you have not left enough capacity in your sump.

For ato, I made a mark with a permanent marker on the glass, outside of the tank.
If you look at the waterline, it's there.
Make the top off line high enough so the pump doesn't suck air.
I'm just doing a simple drip top off for now.

You don't "find" your level for ato, you set it by adding saltwater.
Then keep it at that level with top off of ro/di.

[mrpergo]

Originally Posted by TankStudy

That is a lot of work turning things on and off. Take a piece of sticker and mark where your water is good at in the sump, usually by the return pump. When water starts evaporating below that sticker, fill RO/DI water back up to that sticker. This is assuming your topping off by hand.

Hope this helps.

this makes sense .......lol
so it's the return compartment that loses the water first ?
When I get an ATO that is where I would hook the switch?
so the tank stay's consistent and the water goes down in the sump, I put a mark on the sump where the water is in the return, when it goes down top it off with new RO/DI water.......got it

[Mark9]

Yes, the display tank's water level does not not fluctuate.
It will go down daily.

[GhostCon1]

Originally Posted by mrpergo

this makes sense .......lol
so it's the return compartment that loses the water first ?
When I get an ATO that is where I would hook the switch?
so the tank stay's consistent and the water goes down in the sump, I put a mark on the sump where the water is in the return, when it goes down top it off with new RO/DI water.......got it

Wherever your return pump is, that is the area where you will see the effects of evaporation.

[thegrun]

Originally Posted by mrpergo

I was reading Melesreef about sumps and it said to shut everything off let the water drain down back into sump, if there is room left in the return area fill it up.
Turn your pump back on and where the water level is in the return chamber put a mark and that is your max water, and then you top off that area when the water goes below that line.
Is that right ?
I have a 75 gal rectangle with a hob overflow and an Eshopps R-100 sump tank with a Reef Octopus NB-100 skimmer.
What process should I use to find my max water, I've been reading for months and remember reading how to but don't remember where. I know I need to top off in the sump. Just trying to iron out the wrinkles before the residents of the tank get in.....lol
I know I ask a lot of questions but I read a lot which causes me to ask more questions....

Yes, this is the correct procedure to maximize the amount of water in your system. I would make my top-off point slightly lower than what Mel's technique calls for to add a safety zone. Yes, the return pump compartment is the only section where the water level will fluctuate (when the return pump is on) unless it runs dry, so that is where the float switch is located.

[mrpergo]

okay my friends I'm beginning to understand, it could be dangerous.....lol
I'll do it Mels way but leave myself 3" or so when everything is off and done draining down in the sump. I will then fire it up and mark it off.
Thank you all for your help.
I'm sure more questions will follow.

[thegrun]

you'll be advising us in no time!

[Sk8r]

Get a friend to watch the tank level while you watch the sump level, and make sure you have enough free room in the sump to receive the drain-down from hoses and overflow when the pump is turned off.

[mrpergo]

Originally Posted by Sk8r

Get a friend to watch the tank level while you watch the sump level, and make sure you have enough free room in the sump to receive the drain-down from hoses and overflow when the pump is turned off.

Thank You, I have triple checked that and drilled 2 holes in my return just for safe measures. I had a problem when my 55 freshwater was in this spot, the wire for the light was going across the hob filter, the water followed down the drip loop onto the floor to seep through the ceiling below (which is my theater) I noticed the water way down when I had just topped off.
....SK8r I read your sticky for starting your tank. I noticed you like your temps around 80. When I look at fish and coral requirements 72-78, shouldn't you run at 76 with those parameters? Just wonder about your reasoning (I'm sure you have one and I'm ready to listen)