PH, Algae, Plant Observations

[Jeff S]

I have an IBC with hundreds of fish and 2- 45 gallon aquariums with grow beds. My IBC runs like clockwork with the only issue (which I leave alone) of PH around 7.4. The veggies in the GB grow fine but some of them do better in my dirt garden. The Kale is lighter green and started to seem dry in the GB while in the garden it flourishes a nice dark green. Strawberries aren't producing. Got 5 or 6 berries early but none since. I planted cyan pepper seedlings in my GB and garden at the same time and the garden already has 4" peppers on them while the GB has none.

Both my aquariums suffer continuous low PH.... I'm talking 4-4.5. I've added a potassium hydroxide and hydrated lime solution gradually but it never got to a good level. I'm trying something that might be radical now. I have a duckweed bed that I'm going to move. The water in the bed all came from my IBC and now has algae and a PH of 10. I was going to dump it but I've started doing water changes to the aquariums using this water in hopes of raising the PH. I've been doing this for a couple of days now.

Through all of this I haven't lost any fish. I have all Tilapia except for 7 large goldies in one of the aquariums.

I'm looking for thoughts and/or suggestions.

[Alex Veidel]

So, are you running two separate systems then? The IBC and the aquariums?

I would start using some potassium or calcium bicarbonate to get your aquarium's pH up. The bicarbonates act as a buffer, which will help stabilize your pH.

[Jeff S]

Yes there are 3 separate systems, each with it's own GB. The aquarium GBs are small seed starting beds mainly to provide bio filtration for the tanks.The ammonia in the aquariums is always a problem but with the low PH I've stopped worrying about it as long as nitrites are under control and nitrates are good. I'll try the bicarbonates. It does sound like a buffer is in order for the aquariums.

[Jeff S]

Put 1 teaspoon calcium carbonate in each aquarium and voila 6.9pH up from low 4s. Now to see if it holds.

[Alex Veidel]

You'll want to be using bicarbonates, not carbonates. FAR better buffering. Plain 'ol carbonates offer very, very little in that regard.

Jeff S said:

Put 1 teaspoon calcium carbonate in each aquarium and voila 6.9pH up from low 4s. Now to see if it holds.

[Jeff S]

For some reason I have a hard time finding bicarbonates.

[Glenn]

Jeff, The host of this aquaponicsource web site offers Potassium Bicarbonate here: http://www.theaquaponicstore.com/SearchResults.asp?Search=potassium...  in one, two, and three pound quantities for a reasonable price. It should also be available in "food grade form from wne and beer making suppliers, or by one pound or two ounce quantities from health food stores and in the baking and canning sections of most grocery stores. Lab quality or reagent grade is difficult to get but universities and their suppliers are an option.

I hope this helps.

[Jeff S]

Definitely helps. I'll start shopping . Thanks

[Jeff S]

More PH. I think I found out why my PH in the IBC is staying around 7.4. I store tap water in plastic garbage cans to let the chlorine settle out. I tested that water today and had 8.8 in the uncovered one and 8.2 in the covered ones. Never thought much about it before since the tap water is 7.3. Is there a reason why the PH would rise in the trash cans? (They were new when I started)

[Alex Veidel]

Also, Randall recommended this place I believe: http://www.nuts.com/cookingbaking/leavenerthickener/potassium-bicar...