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OK, some advice.

Having a problem with SG. Being replacing water with RO only, yet SG keeps going up.

Should I rather replace a large amount of tank water with RO.

Here are the tank levels:

PH - 8.2
KH - 6
nitrate - <1
nitrite - 0.01
NH3 - 0.05
Salinity - 1.028
Calcium - 420
PO4 - <0.01
 

jacquesb

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OK - cool! Many thanks Warr!

OK - so my last post was that you should add +-3 to 4 litres of RO water per day, and then measure your SG about 30 minutes afterwards (that the RO mixes nicely with the rest of the tank water first). If there's too much water in your tank, you can remove some water (you can put it back to recycle in a container if you want) from your tank before you add the RO water.... Monitor very closely while you are in the process of doing this....
 
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Ok, I have 50 litres ready to go. I will monitor over the weekend.

I am going to get right !!!!!:023::023:
 

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I know - don't worry - you will get it right - OK - 3 to 4 litres out of 500 litres might be a LITTLE too low, BUT you should experiment with this - you might end up going up to adding +-5 to 6 litres in a day, as soon as your salinity has stabilized. FOR now - you will HAVE to add even MORE than that to stabilize your salinity..... (and remove some water in the same process from your tank - otherwize your tank will over-flow :)
 

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Warren, to increase your KH, pop in to your local Makro or Pick n Pay and buy some Robertsons or Buffalo Koeksoda, dirt cheap and works like a bomb.

On your tank I would start off with maybe one teaspoon mixed in a jug of RO water, add it slowly into your tank over a period of about 20 to 30 minutes, a small pour every 5 minutes. Test your reading a couple of hours later or the next day and continue daily as required until you get to a KH of about 8 or 9.

This is another parameter that needs to be continually monitored, at the very least on a weekly basis.
 

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Oh, one more thing, if you bake the powder in an oven it does increase it's effectiveness. I can't recall the exact procedure though, palmerc or Reef Maniac can help with that.
 
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What SG are you aiming at and more importantly..what are you using to measure it with?
 
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I see from your other thread that you have shrimps. Be very careful when adjusting your salinity if you do. They are very sensitive to salinity changes.Make sure the change is very slow.!!!
 
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I can't recall the exact procedure though, palmerc or Reef Maniac can help with that.
If I may :)

Spread a packet of koeksoda in an oven proof glass or ceramic baking dish (not sure of the correct English culinary term...) - don't use any metal dish. Place in oven and heat
at 180°C - 200°C for 1.5 - 2 hours. Allow to cool down in a dry environment and store in an air-tight container.

The baked koeksoda will increase the tank's pH, whilst the normal unbaked variety will initially decrease the pH slightly. You can mix the two components to give a pH of around 8 - 8.5, but I rarely bother with this, as my pH tends to run low.

Be very careful when adjusting your salinity if you do. They are very sensitive to salinity changes.Make sure the change is very slow
Agreed. I would suggest you remove (say) 10 liters of tank water, and then add the RO replacement at a fast drip, using any water container (bucket...) and a piece of airline tubing. Monitor the SG every 30 minutes or so, and decrease the drip rate when you're close to the level you're aiming for. then make final adjustment after a few hours (over night...).

It is important to ensure that you are getting the correct SG reading, so use a good quality glass hydrometer or refractometer, preferably checked with another instrument. Lastly, remember that SG is temperature dependent, and allow for that in your final "aimpoint".

Hennie
 
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I have now replaced 20 litres of tank water with RO. The SG is still 1.028.

Any suggestions ?
 
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I have now replaced 20 litres of tank water with RO. The SG is still 1.028.

Any suggestions ?
What SG are you aiming at and more importantly..what are you using to measure it with?
It is important to ensure that you are getting the correct SG reading, so use a good quality glass hydrometer or refractometer, preferably checked with another instrument. Lastly, remember that SG is temperature dependent, and allow for that in your final "aimpoint".
So, how are you testing the SG, and at what temperature are you taking the reading? Also, have you checked your test instrument against another (preferably known to be accurate) one?

Have you checked the SG of the RO water - it should read 1.000 at 25°C IF the instrument is calibrated to read at tank temperature.

Oh, if you are using a glass float type hydrometer, do you keep it in the tank permanently? This is not a good idea, as algae can grow on the glass, and that will affect the accuracy. The correct way to use is to remove some tank water to a tall container (500ml measuring cylinder is ideal, but a tall transparent vase works just as well) and then place the hydrometer into it.

Take the reading at the BOTTOM of the meniscus.

Hennie
 
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I have replaced 25 litres and SG has moved down to 1,027.

Should I replace 50 litres to get down to 1,025 ?
 

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So, how are you testing the SG, and at what temperature are you taking the reading? Also, have you checked your test instrument against another (preferably known to be accurate) one?

Have you checked the SG of the RO water - it should read 1.000 at 25°C IF the instrument is calibrated to read at tank temperature.

Oh, if you are using a glass float type hydrometer, do you keep it in the tank permanently? This is not a good idea, as algae can grow on the glass, and that will affect the accuracy. The correct way to use is to remove some tank water to a tall container (500ml measuring cylinder is ideal, but a tall transparent vase works just as well) and then place the hydrometer into it.

Take the reading at the BOTTOM of the meniscus.

Hennie
?:wave2::wave2:
 
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So, how are you testing the SG, and at what temperature are you taking the reading? Also, have you checked your test instrument against another (preferably known to be accurate) one?

Have you checked the SG of the RO water - it should read 1.000 at 25°C IF the instrument is calibrated to read at tank temperature.

Oh, if you are using a glass float type hydrometer, do you keep it in the tank permanently? This is not a good idea, as algae can grow on the glass, and that will affect the accuracy. The correct way to use is to remove some tank water to a tall container (500ml measuring cylinder is ideal, but a tall transparent vase works just as well) and then place the hydrometer into it.

Take the reading at the BOTTOM of the meniscus.

Hennie
1. Refractometer, Yes two other units LFS and friend
2. Yes, 1.000 tank running at 26°C
3. No Hydrometer
 
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Hi freind to bring your nitrite and nitrate down dose vodca .3mill not 3mill .3mill per 100lts every day and add good bacteria it works very well your sg you shoud check you testing meter by draing 25lts you should come down to at least 1026 do not drain any more due to shock
 
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Hi freind to bring your nitrite and nitrate down dose vodca .3mill not 3mill .3mill per 100lts every day and add good bacteria it works very well your sg you shoud check you testing meter by draing 25lts you should come down to at least 1026 do not drain any more due to shock
I don't have a Nitrite/nitrate problem. The SG is too high, I have replaced 25 litres and the SG is only come down to 1.027.

That why the question in post #14
 

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