fishchemist

However, on the part about the pH going down , IMO it is unlikely because the OH- mainly comes from the Kalk solution that is added. But surely agree with the Ca2+ being wasted as in the ppt(precipitate) form, it is not made available to the corals. Since the marine tank is alkaline, the possibility of the solid carbonate dissolving is low. So as good as not adding. Sand is a type of silicate and does not contain really contain CaCO3. However, some rocks and corals do contain contains CaCO3.=> not really impt, just feel like saying something

You are really capable! Seen your posting about DIY MH lights. Can DIY nearly everything. Well done! And also thanks for generously sharing your DIY stuff on the forum. I had learnt much. Cheers

Thats what I meant. Agree!

Thanks for taking time to explain these stuff . I had been enlighten. Felt really uncomfortable to add a chemical and not knowing what other parameters could be affected. Really make sense now. Cheers

If you are joining a unit that had gone thru 6 years of ICT, then you are really lucky! I join one in their 12 ICT and now being recycled! Some more must go for a 5 week course and NOT considered ICT!!!!

Which is calcium carbonate, isn't it? Since marine aquarium is alkaline, atmospheric CO2(an acidic oxide) tends to react react/dissolve in the the solution, resulting in the formation of carbonate. However, there are other sources of carbonate in the aquarium eg the LR.

Since Kalk is Calcium hydroxide, I think it is a common effect of some insoluble hydroxides or carbonates, since it is white it might be magnesium hydroxides, Calcium carbonate? The concentration of these ions are high in region when the solution is added hence precipitation tends to occur. But it should soon dissolve as there is a usual strong flow of water in the aquarium. Please coorect me if I'm wrong. Cheers

Yup! No ICT for 7 years since ROD and then PDF all the way.

Me digging non stop, putting up obstacles, walking/running everyway, non stop intensive sun tan, begging for water........... Next year again Got 9 more to go........Help.........Medic!!!!!!

IMO if I would to increase the pH of a solution, I would add a basic salt eg gulconate. This salt can increase the pH slowly and also act as a buffer. If I would to increase the concentration of Ca, I would add a neutral Ca salt. From a chemical point, we should not adjust the pH via direct addition of acid or alkaline. Are there some aspects about the marine tank that I am ignorant about? Cheers

If kalk = calcium hydroxide, then it should increase both the Ca and pH, isn't it? However, isn't it risky to pour alkaline into marine tank?

I too from 663 SIR. Finished mine this year. Nearly died. Use to think that PDF is a paradise - Plenty of Drink & Food. In fact jump for joy when posted there. Now live to regret it.

Yes!!!!!! Defence exercise very shiong man! You are from one of the units there?

I overlooked the fact that Ca ions can precipitate out carbonate which can cause the pH to drop slightly. However, I am sure that the pH will surely be well above 7. I had just check with my lab technicians regarding CaCl2. They do sell anhydrous ones. IMHO given the high humility here, they will get hydrated in a short period of time - just like leaving potatoe chips for a couple of hours, they become 'lou hong'. Will update you on the price when I get hold of the catalog

Paiseh, paiseh . New to this hobby. Just found out that Kalk is a short form for Reefez Kalkwasser - a chemical additives. Will be more careful in the future.

I think it is chalk? Chalk - Calcium carbonate - (CaCO3) which can also act as a buffer.

I think that it is unlikely that Lab grade calcium chloride (CaCl2) would be contaminated by other form of harmful heavy metals. Well it depends on what type of heavy metals we are referring to, Ca is a type of heavy metal too but it is benificial. However, I am not sure if the type of Ca ions that is introduced from CaCl2 is the type that will be assimilated. Some times these metals must exist in a certain complex form before the corals can assimilate them. CaCl2 is a neutral salt, dosen't cause hydrolysis of water. That is the pH should not be much affected. I doubt its usefulness as a drying agent considering the ones we are getting as it is already hydrated - it had already absorded moisture. I can check on the price of the chemicals, but that might that a few days as I am on holiday now. Cheers

Hi everyone, I am looking for a TECO RA680 chiller. Any offer? Cheers, Simon