Bubbles in the pipes
How to prevent bubbles in the reagent line or in the Water In, Kh, Ca or Trace lines (tubes). Como prevenir que se formen burbujas en el tubo del reagente, o en los del Water In, KH, Ca o Trace.
The presence of air or gas bubbles in pipes is normal and to be expected, it is called cavitation and is due to pressure changes. If the pressure is lower than atmospheric pressure at any point in the tube, gas bubbles will form, i.e. the liquid will become gas.
Reagent
In the case of reagent, this will cause less reagent to be dosed than the system actually thinks, so it will need to add more reagent during the analysis, causing the KH result to be higher than it actually is.
Water In
In the case of Water In, the effect is the opposite, as the beaker is less full, less reagent will be needed, and the KH will give a lower value than it actually is. However, in the case of Water In, the influence of the bubbles is lower.
KH/Ca/Trace
In the case of dosing machines, it will mean that it doses less than it has to. So the system will end up determining that the consumption is higher than it actually is. However, if the bubble level is stable, the system will compensate for this, and will add what it has to add, even if it thinks it is more.
How to avoid or at least reduce the level of bubbles
Adjust the number of daily analyses. The more daily analyses, the less presence of bubbles. However, too many analyses can over-segment the dosages, causing them to become inaccurate. Dosages of less than 5ml are not advisable (at least 10ml is ideal). If your daily dosage is high, increase the number of tests. If it is low you should not go above 6/8 tests per day.
Examples:
- If your daily dosage is 240ml, you could do 24 tests with one repeat: 10ml x 24 tests or 12 tests with one repeat: 20ml x 12 tests or 12 tests with two repeats: 10ml x 12 tests x 2 repeats.
- If your daily dosage is 120ml, you could do 12 tests with one repetition: 10ml x 12 tests.
- If your daily dosage is 60ml, you could do 6 tests with one repetition: 10ml x 6 tests. And the minimum maximum would be 12 tests with one repetition: 5ml x 12.
- If your daily dosage is 40ml, you could do 4 tests with one repetition: 10ml x 4 tests or 6 tests with one repetition: 6.67ml x 6 tests. In this case the minimum would be 8 tests.
It is not possible to set the autoBalance to less than 4 tests per day. Because that would cause inaccuracies and cavitation problems due to lack of movement.
Avoid elbows and connectors. Narrowing of the tubing lowers the pressure at these points causing cavitation and bubble formation.
Make a diagonal cut in the tubes entering the canisters (KH in, Ca in, Trace in and reagent). This will prevent voids and therefore pressure drops. In addition, the tube should enter the canister with a certain clearance, so that the same pressure is maintained inside and outside the canisters. If the tube fits tightly, make a hole so that air can enter freely.
Do not insert the dosing tubes (KH out, Ca out and Trace out) into the sump or aquarium, but let the liquid fall out. This way we will maintain the atmospheric pressure at the tube outlet.
The water inlet is also important, it should not be an area with a lot of current or bubbles, as this will cause a drop in pressure in the tube. Try changing the water inlet position if you have problems with bubbles or errors in the KH reading.
If you use Reef Balance without pre-mixing (powder), make the mixture ahead of time, i.e. don’t use it as soon as you mix it. And always store in a dark place.
Make sure that the temperature is the same in the tanks and along the tube. Temperature affects the pressure and can cause cavitation.