A couple of questions that could do with answers please

Hi just wanted your views on ageing water as i don't do it,i go from tap through HMA filter them direct to tank.


The questions i'm asking are should i aerate or not if i age the water?


Also as i have just set up a tank for my niece which is home to 6 silver ghosts that came from helen & as of today 4 young Koi that where bred by me. well what i would like to know is what should be the Mix of RO to HMA, as her dad used to keep Marine & has given her his RO filter & she also has an HMA filter that i gave her. I have said the mix should be at least 75/25 but her dad has said something different so i thought i would ask, as when i kept Discus 75% RO to 25% HMA was what i used & to great sucess.She has been using 100% RO but with Discus remin & if i can help her save money by not having to buy the remin i will, i have also told her that she doesn't really need the RO filter but dad has given it to her & she would also like to listen to him & get him involved. So any views would be more than welcome.

Many Thank
Paul

I don't have much practical experience of HMA filters, but my understanding is that they are designed to remove chlorine, and therefore using the water straight into an aquarium should be OK, provided you take care not to cause too drastic a temperature change.

As to blending HMA and RO water, the ratio will depend on the KH (Carbonate hardness) of the tap water you start with.
Although it is possible to run tanks with lower levels, I recommend that in general the KH of the Aquarium water should be maintained at a KH level in excess of 2 dH. (Note KH, carbonate Hardness is not the same as GH, General or total hardness) At levels below this the pH can become very unstable very quickly, especially if the tank is fed heavily, and the water not changed frequently.

So if your niece's tap water is very soft, with a KH of 2 or less, then I would recommend using 100% HMA water. If on the other hand it has a high KH, I would suggest blending to bring the KH down to close to 2.
eg
KH = 4 use a 50:50 RO:HMA mix
KH = 6 use a 67:33 RO:HMA mix
KH = 8 use a 75:25 RO:HMA mix

Remember that the KH of tap water can vary significantly throughout the year, and even on a day to day basis, so check the actual KH of both tank and tapwater on a regular basis.

Thank you Rob for yet again another indepth answer,i checked her Kh last night & it was a tad over 8 & her Ph was also 8 which is typical of london water.So i have let her & my brother inlaw read your answer & they are now going to slowly adjust accordingly until they have a 50:50 mix.

The HMA filter removes clorine & cloromine as well as a good pecentage of other heavy metals found in tap water but it doesn't strip the water like an RO filter so is ideal for angels unless keeping Altums as it doesn't soften the water like an RO filter, plus there is no waste unlike the RO filter,so if you happen to be on a water meter its a handy bit of kit & pays for itself after a period of time.

Oh Lord, my head is spinning. KH, GH, PH. I'm gonna have to lie down. Lol

Any excuse Helen we all know.