Question: SG

Tankerini · July 30th, 2008

Quite a few questions on this;

How do you get the level of S.G you want? i.e if you want it to be 1.201 - 1.204 or at the higher end 1.203-1.206.

Do you buy salt mixes for the level of SG you want or can you buy any salt mix and it will tell you on the back the amount of salt to add for the level of SG you want?

Also is there anything that can affect your SG levels to go up and down in the tank? Or once its at the right level its ok?

What happens to the fishes/corals if it goes out of there recommended range?

Wolfgang8810 · July 30th, 2008

specific gravity or salinaty can be adjusted by the ratio of salt to water. If your salinaty is high you take some saltwater out of the tank and replace it with freshwater. If your SG is low you can add Saltwater for evaporation top offs and that will raise the Salinaty.

When you buy your salt mix it has instructions on the back telling you how much salt you put in per gallon of water. I believe it is a half cup/gallon.

Evaporation effects the level of your SG. Salt dosent evaporate so when wwater evaporates from your tank it leaves its salt behind which creates a more concentrated amount of salt in the tank.

It depends. How far out of the recommended range are you? I keep my small tank at 1.025 and im keeping every kind of coral successfully. In my 90 gallon tank my SC is at 1.029. A little high but i will bring it down over the next few days.

I hope this helps.

Slug · July 30th, 2008

Quote:

Originally Posted by Wolfgang8810

Specific Gravity or salinaty can be adjusted by the ratio of salt to water. If your salinaty is high you take some saltwater out of the tank and replace it with freshwater. If your SG is low you can add Saltwater for evaporation top offs and that will raise the Salinaty.

When you buy your salt mix it has instructions on the back telling you how much salt you put in per gallon of water. I believe it is a half cup/gallon.

Evaporation effects the level of your SG. Salt dosent evaporate so when wwater evaporates from your tank it leaves its salt behind which creates a more concentrated amount of salt in the tank.

It depends. How far out of the recommended range are you? I keep my small tank at 1.025 and im keeping every kind of coral successfully. In my 90 gallon tank my SC is at 1.029. A little high but i will bring it down over the next few days.

I hope this helps.

Agreed.

When it gets to low or to high you will start to notice coral stressing out. SPS polyps closed, zoas shrinking or closed, GSP pulled in. You'll know when your coral is stressed. If its way outside the good range, coral can start dying. Plus your LR will start to die off if the SG is to low and near the freshwater range.

Tankerini · July 30th, 2008

Thanks guys!

I was in my LFS this morning, and read the back of the salt mix instructions so get it now

If your doing a weekly water change, this should keep the sg in the tank quite stable as not much water will evaporate in this time right? (depending on outside influences of course, room temp etc).

Nice bit of info on the corals reaction to SG levels wolfgang

Hmmm now you mention it I did notice some of that going on in a tank in the LFS, I better let them know lol. Btw whats gsp?

What salt mix do you two use? They only had Tetra (Which Im thinking is !) or seachem.

Wolfgang8810 · July 30th, 2008

GSP= Green Star Polyps

yes weekly water changes will be a good idea. However depending on your lights you will have more evaporation. I have a 150 watt Metal halide over ym 24 gallon tank and i lose 2 gallons to evap/week. In my 90 gallon tank I have 300 watts of PC and i lose 3 gallons of water to evap/ week. It depends on surface area really.

If you do get5 some evap and then do a water change before topping off the tank with FW it will gradually boost your SG so weekly FW top offs are a good idea too. :-) Make sure you use either distilled or RO/DI water for top offs. Tap water is bad.

Slug · July 30th, 2008

I use Instant Ocean. Out of Tetra and Seachem i'd personally be inclined to go with Seachem. I like Instant Ocean though.

I do weekly water changes, but i top off everyday. Having a 250w MH over an open top tank and a fan blowing across the water speeds up evaporation a lot. Plus i have a 10gal tank, so i need to stay on top of evaporation or else things can go bad fast. You don't have much slack in a smaller tank.

ReeferMadness · December 8th, 2008

Quote:

Originally Posted by Wolfgang8810

Make sure you use either distilled or RO/DI water for top offs. Tap water is bad.

What is ro/di water or distilled water? why are they better then tap water?

Peterpiper · December 8th, 2008

reverse osmosis, deionization and distilled water dont have all the chems that tap water does ie phosphate chlorines etc

ReeferMadness · December 9th, 2008

so wat is the best way to go about water changes? where should i get my water? i have heard lfs may sell water, people buying purified water from the grocery store, or treating tap water. Any suggestions?

au01st · December 9th, 2008

Dang, I lose almost 2 gallons per day. I fill up my auto top off system on Thursday afternoon, it holds 6 gallons max, I usually put in 5. On Sunday afternoon I have to fill it up again, lol. Open top, 216watts of T5, lots of surface agitation.

The auto top off only cost about $20 to set up and is definitely worth it, as I don't have to worry about SG fluctuations. I can't wait to get my RO/DI unit plumbed how I want with a direct line to the auto top off, then I literally won't have to worry about topping off water, it will all be automatic.

I use Instant Ocean Reef Crystals, but out of those two, I would use the Seachem.

Rbacchiega · December 16th, 2008

Invest into your own RO unit. That's the best way to go. For innitial setup, buy it from a store (no waiting!) and then you can makeup your water in those plastic garbage bins. I use two 40 gallon garbages for RO water and then another 29 gallon for Mixing the salt in with the RO and pumping it back into the tanks

nemo addict · December 20th, 2008

just pointing out 1 thing which i could not see being explained you do not need salt mix when topping up just plain water as salt doesnt evaporate this is why you mix salt in a water change to keep the same level , if you loose water add back to orignal level and your sg will be back to how you origanally started

Fish Forum Thread Tools
Show Printable Version