Phosguard and falling KH result ?

[Tazman]

Hi,

Thank you for this support forum.

Following an increasing of Phosphate in my planted aquarium (470L) due to the food for Discus (in growing stage), I use your Phosguard.

My parameters was KH 5, GH 7, PH 7, NO3 5, conductivity 400µs, PO4 2 !!
The vegetation absorbs all nitrates but not the Phosphate. The result was an explosion of algae.

I followed instructions and use Phosguard during 1 week. The result was directly PO4 0,2.

It is the objective to decrease PO4… BUT, hardness has fallen ! KH0 !!!???

The result with the added CO2, my PH decrease to 6 !!!!!????? ARGHHH…

So I take off Phosguard from my filter and did water changes.
Even if I changed 15% of the water every 5 days, My KH stay at 0 ? and my PH 6 ?

Today I stop the CO2 adjunction to avoid acidosis without control.

My question is “why” Phosguard drop the KH, and could you please explain what maens the mentioned instruction, “except water buffered by phosphate” ?

Thank you for your support and your help in my situation to know what I have to do now
Regards

[Tech Support HK]

Hi Tazman,

I am sorry to hear about your sudden pH and KH fluctuation. PhosGuard will not result in the lowering KH. It will lower pH if the current buffering system is phosphate based, since PhosGuard does remove phosphates. If a phosphate based buffer is used to stabilize pH, then PhosGuard will unfortunately remove the buffering system.

Would you mind answering a few questions? Hopefully the answers will shed some light on the situation you have experienced.

1. What product do you regularly use in order to buffer your aquarium?
2. What test kit are you using in order to test for KH?
3. Do you use RO water or tap water during water changes?
4. What other chemicals/supplements do you regularly use?


Thank you for your patience, and we look forward to your response.

[Tazman]

Thanks for your prompt reply.

To reply to your question:

1.What product do you regularly use in order to buffer your aquarium?
I never used product for buffer my water. I use natural balance between food, fishes, plant, and water changes.

2. What test kit are you using in order to test for KH?
Tetra kit (for information all my tests are bubbles test, mainly JBL)

3. Do you use RO water or tap water during water changes?
I use 100% tap water from many years with parameters: PO4 0, NO3 20, KH 5, PH7.5 conductivity 380µs

4. What other chemicals/supplements do you regularly use?
Only Saechem flourish oligo one time per week after water changes and CO2 during lightning period, just 1 bubble/min for 400 litres.

Yesterday evening after 1 day without CO2, my PH was back to 6.5 (KH undetectable with my test).
I’m sorry but I don’t understand the relation between my tap water KH (5) and Phosphate buffering system in the same water as PO4=0 ?? I will check again PO4 in my tap water this evening.
Can I use Phosguard temporary with a solution to buffer my KH ?

I know that my exceeded Phosphate came from a lot of Discus food as I didn’t meet the problem with Scalares before…
Thanks for help

[Tech Support HK]

Thank you for providing us with those answers.

PhosGuard should not have lowered the pH since you do not have a phosphate based buffering system in place. Since your alkalinity is comprised of KH from the tap water, it will be perfectly fine to use PhosGuard to remove the phosphates from your aquarium.

How long have you been using CO2 on your aquarium? A KH of 5 really is not high enough to keep your pH above 7.0 while implementing CO2 injection. You will really need to increase KH to 6-8 in order to keep a pH of 7.0 while maintaining the ideal CO2 concentration for an enriched tank.

[Tazman]

Thank you,

In fact, I have no problem with a PH under 7, I can accept PH6 as my aquarium is an Amazonian biotope.
My problem is to keep a minimum KH to avoid fluctuation. A target of KH3 or 4 is good to keep stable PH around 6.5-7 for me.
To reply to your question, I use CO2 adjunction from 3 years to decrease my PH(tap water 7.5) and for my plants.

I repeat but a PH6 is not a problem for my biotop. It could be fine in fact. But I don’t want to take risk of uncontrolled KH0 and acidosis.

I’m not chemist and I always don’t understand the falling of my KH 4(alkalinity from tap water) to 0 in one week with Phosguard ? I never saw my KH under 4 before...

Thanks for your support

[Tech Support HK]

Hi Tazman,

Is there a way to ensure that the KH test kit is still providing accurate results?

[Tazman]

Hi,

If my understanding is well, yes my KH test is always good.
I can buy another, or test my aquarium water in shop, but I think my KH test is ok:
- My tap water is always tested KH5
- I never succeeded to decrease my PH under 6,8 with CO2 before this situation with KH tested 0. And now my PH fall to 6 without any change of CO2 quantity added.

I will do again KH and PH test this evening (tap water and aquarium).

If you are interesting, except if solution found before, I want to do a test KH evolution on two sample:
- One sample tap water alone
- One sample tap water with Phosguard
I will test on a week…

[Tech Support HK]

Sounds good! Please let us know the results