Jump to content
rawprawn

Water keeps buffering to 8+ PH

Recommended Posts

rawprawn

For 18 months I've been struggling to lower the PH of my cherry tank, but no matter what I do it ends up back at 8.4 on my meter/8+ with my API kit.

Last major check about a week ago:

 

PH 8-8.4

TDS 200ppm

GH 7

KH 5

Ammonia/Nitrate/Nitrite all 0.

 

The tank has been running for 18 months almost and all looks well.

 

Substrate is Serenity Black Diamond sand, filter medium is some bio balls that came with the cheap cannister filter I bought and topped off with ceramic noodles from Guppies.

 

As the tap water is also a very high PH here, I've started using pristine rain water from a farm in the upper Hastings valley (PH 5.6) with the prescribed 2 spoons of Saltyshrimp GH/KH per 20L, which seems to bring it up to 7.2-7.4 PH.

 

I've done about 6 weekly 20L/10% water changes (4 foot tank) with this water with no change whatsoever in PH, last time I did 40L.

 

It sticks so solidly at 8.4 that I'm concerned something is buffering the water.

 

I've got some of the sand from the tank in a container with RO water which is showing no change, but I'll give it 20hrs and check again against a control sample which is 7.4.

 

Only other thing I can think of is my driftwood, which is a big 2m piece I found on the beach and cut in half, then pressure blasted before I set up the tank. It's been there from the beginning and is covered in java moss.

I've got a couple more small peices from the shop that had and Anubia on one and Java fern on the other.

I'd have thought this much wood would have made the water more acidic.

 

I really don't want to get into PH up/down drops, I'm much more into letting the tank find its own ph level, but this seems odd.

 

I'm an instrument tech and all my gear is calibrated. It's not that.

 

Any suggestions what I'm looking for here?

 

Cheers.

 

 

 

Share this post


Link to post
Share on other sites
perplex

id test your sand like your doing, i had that issue, i just left it over night in a super small amount of water, make sure you give it a good wash with the water that is your test water, check the ph before, then 1 day later

 

your rain water is 5.6ph? thats abit weird for rain water i thought, TDS must be higher in it than normal

 

how long have you had the drift wood in the tank soaking?

  • Like 1

Share this post


Link to post
Share on other sites
rawprawn

Cheers for the reply.

Yep, rinsed the sand in the test water thoroughly, and it looks like it might be changing the ph already after a half hour.

My thoughts exactly, I'll check again am.

Pure rainwater is slightly acidic due to some sort of ionization or something as it falls. I certainly don't claim to be an expert on that, but I did check with mr Google:

https://www.google.com.au/search?client=opera&q=natural+ph+of+rainwater&sourceid=opera&ie=UTF-8&oe=UTF-8

The driftwood has been in there over a year now.

Edited by rawprawn

Share this post


Link to post
Share on other sites
fishmosy

Rain dissolves CO2 which makes it slightly acidic. In industrial areas, it dissolves pollution making it very acidic. 

Share this post


Link to post
Share on other sites
perplex
2 hours ago, rawprawn said:

Cheers for the reply.

Yep, rinsed the sand in the test water thoroughly, and it looks like it might be changing the ph already after a half hour.

My thoughts exactly, I'll check again am.

Pure rainwater is slightly acidic due to some sort of ionization or something as it falls. I certainly don't claim to be an expert on that, but I did check with mr Google:

https://www.google.com.au/search?client=opera&q=natural+ph+of+rainwater&sourceid=opera&ie=UTF-8&oe=UTF-8

The driftwood has been in there over a year now.

yea, just see what it is like in the morning, give it abit of a mix before you test since the water wouldnt be moving

Share this post


Link to post
Share on other sites
rawprawn

Yep, straight up to 7.9 overnight.

Fairly safe to say it's going to be at 8.4 soon enough.

So much for Serenity's BS claims of its sand being inert. Bloody frustrating as the whole time I'd dismissed the substrate being the issue due to what I was told when I bought it.

Not sure how to play it from here....

I was already going to set up a second tank to improve my cherry line, but I'll probably move the lot now.

I must say the thought that has crossed my mind is that this would make a good Sulawesi Cardinal tank....

Can anyone confirm that Piscies NZ Black Iron sand is inert??

I'd hate to buy a load of that and have the same thing happen.

 

 

Share this post


Link to post
Share on other sites
s1l3nt

Yes, Iron Sand is inert. I've got it in a few of my tanks without issue. Be careful with magnet cleaners near it though...

  • Like 1

Share this post


Link to post
Share on other sites
perplex
2 hours ago, rawprawn said:

Yep, straight up to 7.9 overnight.

Fairly safe to say it's going to be at 8.4 soon enough.

So much for Serenity's BS claims of its sand being inert. Bloody frustrating as the whole time I'd dismissed the substrate being the issue due to what I was told when I bought it.

Not sure how to play it from here....

I was already going to set up a second tank to improve my cherry line, but I'll probably move the lot now.

I must say the thought that has crossed my mind is that this would make a good Sulawesi Cardinal tank....

Can anyone confirm that Piscies NZ Black Iron sand is inert??

I'd hate to buy a load of that and have the same thing happen.

 

 

i had the exact same issue, it said it was neutral ph, but it wasnt.... and i thought the same thing, testing everything else but the gravel...

 

what i did to make sure my gravel is inert, since i wont trust what they say now, is find a fish shop that has gravel out of bags, find some you like and see if you can take a handful home to test

 

 

  • Like 2

Share this post


Link to post
Share on other sites
rawprawn

Must say I'm not at all impressed with the Serenity sand, which is still sold today as inert.

As a noob I've fallen into the trap of believing them, and with the local water being known for being very alkaline, I've searched for other reasons for ages.

It was only when I started adding low ph water and saw it rebound to precisely the same place over and over that I started to wonder about buffering....now I know.

Just got 2x 20kg bag of iron sand from the local Petbarn for 45 bucks each.

I've found a cheap 5 footer with a canister and I have a spare chiller, so now it's a matter of setting up and cycling a new tank.

Lessons learned.

Share this post


Link to post
Share on other sites
perplex

just test the sand anyway, never hurts

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Must Read SKF Articles

  • Register today, ask questions and share your shrimp and fish tank experiences with us!

    Join Our Community!

  • Posts

    • jayc
      ph dropping is part of the nitrogen cycle. That means the bacteria is doing it's thing. A water change with higher pH water is necessary now to avoid the cycle stalling. The prawn growing fur is also normal, as it is decomposing, and fungi are starting to break it down. Let the biofilm grow as that will be part of the shrimp's diet once you add some in. If it's hindering your view, scrape it off the front glass only, but don't syphon it out. The dislodged biofilm from the front glass will settle somewhere else in the tank.
    • sdlTBfanUK
      Its good to hear that the fur growing on the shrimp is 'normal', I may leave them in until thursdays usual maintenance day then. Todays readings are as before nitrate 25, ammonia and nitrite 0! I could get someone to get me some duckweek from the lake but I remember how hard it was to get rid of it before, so am a bit reluctant to go that route, but it should bring the nitrates down a bit??? You should leave the biofilm in the tank, the shrimps will thoroughly enjoy that when they get into that tank. Simon
    • sdlTBfanUK
      As you are aiming for TDS150 and the tank is near that now at 147 you just make the new water up to near as you can TDS150 and if you keep topping up with pure RO water between changes this would be the normal routine from now. Getting a new TDS meter was the right thing to do as they are cheap enough and hopefully it will be more accurate? As someone said before, you can get a rough idea of whether the TDS reading is right by doing a GH test as using RO water and remineraliser those figures should be related. Probably best to test some mineralised water before you put it in the tank though! Good that you haven't lost any more shrimps, hopefully that continues and all should be straight forward now. Simon
    • jc12
      Thank you. Yeah they are great quality discus of German lineage. Due to family and young kids, I was not able to devote my time to them as much as I would like to so I have since sold them back to the person who sold them to me in the first place. He has been a discus breeder for many years so I know he will look after them well and keep their progeny going within Australia. Thank you. This rack is still running but I am planning to strip it all down, move it to the garage and set it all up again.
    • supermansteve32
      Okay so I haven't done a water change in weeks because I thought the TDS needed to get closer to 150 before changing and my TDS meter continually kept reading 108 to 114. Sho I went and bought a new TDS meter and it's different from my old one.  The new one vs my old one: my water in tank 147 vs 103, water using the correct salty shrimp mix to RO water 88 vs 66. So I'm going with the reading on my new TDS meter.  So it's time for a water change.  Should I replace the water with the 88 TDS or put some more mix in until it's above 100 (since CRS parameters should be 100-200)? Thanks again everyone
×