Very Low Ph

[Dorsal]

Hi all.

I have a real problem with low PH that I have only just discovered. I have two tanks that I have been running for some time (It's a while since I did any testing). Anyway, probably a year back I moved to doing water changes with the water from my rainwater tank. It was a real timesaver. However I've now found that the water is PH5 coming from the tank! Here are the details.

Tank 1. 300l planted rainbow tank. It has many species of Australian Rainbows, as well as some smaller tropicals (Long Fin tetras) and two large catfish. I have lost a number of Rainbows and catfish recently. Now I know why! Current PH = 4!

Tank 2. 500l Mixed Malawi Cichlid tank. It has very good filtration and a light loading of fish. It also has the type of gravel that boosts ph. It's current PH is about 6.3 which is well above the rainwater that I've been putting in. All the fish seem to be healthy.

Both tanks get 30% water changes and cleans every 2/3 weeks. The local tap water is around ph7 but as I said I've been using ph5 rainwater for some time!

So, can anyone suggest any way of getting the first tank up from ph4 with out killing the fish! Thanks!

 

[WILDER]

If the ph is altering fast they can die of ph shock.
What ornaments do you have in the tank and what substrate.
Something in the tank is lowering your ph.
Might be better of placing this thread over in tropical discussion.

 

[Dorsal]

If the ph is altering fast they can die of ph shock.
What ornaments do you have in the tank and what substrate.
Something in the tank is lowering your ph.
Might be better of placing this thread over in tropical discussion.

Hi.. thanks! The only ornament in the tank is a small log, but it's been in the tank since it was set up 4 years ago. I see the problem as at the very least to be that the rainwater that I'm using for water changes is PH5. So clearly this is a problem. The tap water is is a smidge over 7 so maybe I need to use that.

However I agree with you that I need to move it up very slowly. This is what I need suggestions for!

Also, I have a water ioniser that can generate very alkaline water (Ph 10). I could feed a little bit of that in **very slowly** say a couple of litres a day.

 

[WILDER]

I would find out what type of wood it is in your tank as bog wood can lower ph.
You will get alot more help over in tropical discussion, lots of experienced members go over there.
Just copy and paste your thread to tropical discussion.

 

[Dorsal]

Ok, will do. Thanks.

 

[Dorsal]

Well I didn't get to moving the thread so I thought I'd give an update. I added some crushed coral to the filter and have been doing small (5%) water changes with the higher PH tap water. So far I've gone from 4 to 6!. From what I've read the danger should now be largely reduced. I'll now slowly increase the PH over the next few days.

 

[WILDER]

if the ph raised slowly the fish should be ok.
Becareful with water changes as large water changes can change the ph to fast.