Transitioning a stocked tank to have more acidic water without causing cycle crash

[apisto2024]

I am wondering how to go about with this one. I know my tap water is harder than my head (Hello SoCal!). How would you go about with the transition from high ph, high tds tank without causing a killer cycle crash? The acidic beneficial bacteria will have to take over but how to do it gradually?

 

[MacZ]

You can't crash a cycle. It's just a transistion with no real dangers attached. I've done it and dozens of others here and elsewhere under my guidance.

Gradually raise the amount of RO by doing partial waterchanges with it. 20-30% each waterchange, with 3 changes a week over the course of 2-3 weeks and done. But I'd establish the plants we talked about while you do it. While Ammonia is only a problem with high alkalinity you will rather have to keep an eye on NO2.

But considering the low stocking densitity and the plants that will be added, there is no real risk.

 

[MacZ]

Also you're not changing to more acidic water, you're changing to softer water. Acidity and alkalinity do not automatically change with it.

 

[MacZ]

And another addition: You are aware, that after the transition you have to keep using RO, yes? You can't switch back and forth.

 

[apisto2024]

Also you're not changing to more acidic water, you're changing to softer water. Acidity and alkalinity do not automatically change with it.

Yes. But since i would be adding dead leaves and stuff, not sure how fast it would lower the ph. Would it be fast enough to shock the non acidic bacteria? Those were the questions in my head

 

[apisto2024]

And another addition: You are aware, that after the transition you have to keep using RO, yes? You can't switch back and forth.

Also yes. Also will have to keep measuring chemistry due to evaporation, residual hardness and stuff. Thanks! I think im convinced!

 

[dw1305]

Hi all,

Yes. But since i would be adding dead leaves and stuff, not sure how fast it would lower the ph. Would it be fast enough to shock the non acidic bacteria? Those were the questions in my head

On UKAPS we've spoken recently to some of the scientists involved in looking at nitrification in aquarium filters and you might be interested in reading the whole thread.

<"https://www.ukaps.org/forum/threads/correspondence-with-dr-ryan-newton-school-of-freshwater-sciences-university-of-wisconsin—milwaukee.71023/#post-711158">

But I'll abstract Dr Newton's comments here.

......... It is a good question to ask where the initial inoculum of nitrifiers comes from & it is a question that I do not have a definitive answer. Nitrifiers are present in many environments because they can live with comparably low external nutrients (carbon particularly). There are a couple of good possibilities, 1) the water - most municipal water systems contain some number of nitrifiers, which then come out of your residence tap; 2) the plants - nitrifiers are also commonly associated with plants. Or, it could be they drift in from the air - seems less likely, but it is not impossible.

If you do need to add nitrifiers the best source is from an aquaponics or aquaculture system that is already running and removing ammonia. Some water or sediment/soil or part of the biobilter (if there is one) is an excellent starter. Without this source as an inoculum then you could add some roots from plants from any other tank that is running - these are likely to have nitrifiers associated with them. A small clipping put into the tank would be enough.

In some lab tests we found that adding previous material from a running biofilter could reduce ammonia oxidation start-up time from 2-3 weeks to 2-3 days. We also tested a commercial product of nitrifiers & it did decrease the time to ammonia oxidation start-up. It was slower than our biofilter material transfer, but much quicker than doing nothing. However, the microbes present in the system from the commercial product disappeared over a few weeks and were replaced by those more common to our system. So, it seems some products could help “jump-start” the process, but it will be a lot less predictable and ultimately may not determine what microbe succeed in the long run.

cheers Darrel

 

[apisto2024]

Thank you all for your input! I was sure the only logical way is gradual but better be sure!