New pool owner questions

[sarturo]

So I have had a small Intex pool for a month now, water has been crystal clear. Been using the following weekly additions: 10X 1" Bioguard SilkGuard Complete (Trichlor) tablets, 1/3 lb Smart Shock (Dichlor) and 3/4 fl oz Backup 2 Algecide.

Being somewhat OCD I found the pool math app to track everything. The past 2 weeks I've had my pH drift upward to 7.8 and have lowered with lo 'n slo (Sodium Bisulfate). Took my water to the pool store yesterday to get tested and got the following numbers with pool store recommended numbers in parenthesis:

pH: 7.7 (7.4-7.6)
TA: 97 (125-150)
CH: 161 (172-225)
FC: 1.9 (1-4)
TC: 2.1
CYA: 72 (30-200)
Phosphate: 1026 (0-500)

I've been logging everything in the Pool Math App and its basically telling me to do the opposite of what the store says for TA. Store says to raise it with 2.5 lbs of balance pak 100 (baking soda) and to add 0.5lb lo 'n slo (Sodium Bisulfate) to lower my pH. But pool math is saying my TA is too high and that it should be 50-90, add ALOT more chlorine(6-8 ppm) for my CYA level and that pH is fine. Suggestions? I'm tempted to just leave TA alone. Why is there such a big difference between the TFP suggested numbers and the Bioguard suggested numbers?

 

[thetekgeek]

Welcome to the forum. The methods taught here are different than you'll find recommended by the pool store. We do not trust their testing either. IF their testing is correct, you are primed for an algae bloom right now. You have some choices ahead of you. The method taught here is built around owner testing and adding only the chemicals that the water needs and the owner knowing what the outcome will be. A 4000 gallon pool is fairly small and you could treat it as a seasonal pool, outlined here: Guide for Seasonal/Temporary Pools - Trouble Free Pool

Or, you could also go the full route, but to do that you'll need a test kit. See: Test Kits Compared - Trouble Free Pool for the recommended test kits.

Also please read ABC's of Pool Water Chemistry - Trouble Free Pool and get familiar with this: Chlorine / CYA Chart - Trouble Free Pool

If your pool store test is correct, you have too little Free Chlorine for the amount of CYA you have in the water. You'll see algae starting to grow very soon if you do not get some chlorine in the water asap. You'll want to use liquid chlorine/bleach for that because the tablets and dichlor you have been using are making that problem worse.

There is no reason for you to be using Lo n slo, you can simply use muriatic acid for PH control. It is cheaper and does not add other things to the water.

Again, this is all up to you. However, you cannot mix our methods with pool store methods. They simply do not mix. Let us know how you want to manage the pool and we can point you in the right direction. You might start by ordering a proper test kit, exchanging half of the water and then adding 5 ppm FC using bleach each day until your kit arrives. When it arrives, test the water and post the results here and you'll get sound advice, save alot of money and have control of the water you're swimming in.

 

[sarturo]

Well I'm probably going to keep using the trichlor pucks until the container is empty (it was expensive), then switch to liquid chlorine ( I also can't find it at the moment). Ace, Lowes, and Home Depot didn't have any in stock yesterday. I picked up a 6 way DPD test kit (Taylor K-1004) and some Taylor 7 way test strips at the pool store the other day. Used them for the first time yesterday.

I added 5.7 oz of Smart Shock (Dichlor). I want to use what I have up. I still have 1-1/3 lb of this on hand and half lb of of Burnout 3 (Cal-Hypo 57.8%)

This morning numbers were:
FC: 3
CC: 2
pH: 7.5
TA: 100
water temp: 82 F

test strips all confirmed those numbers except the TA was way off (maxed out on the strip)
TH: 200
CYA: 70


Yesterday when I tested with the kit I got FC of 2 and CC of 0 ( should note I didn't hold the dropper completely vertical. So I'm not sure if I should just discount those numbers. I didn't realize this mistake until I reread the instructions this morning.

 

[PoolNewb2020]

Welcome!
It's your choice, but if the pool store test was somewhat correct and you already have CYA of 70ppm, and actually since it came back as 72, I would be inclined to treat it as 80ppm. you are on the verge of going to 100ppm, at which point you will most likely have to drain half of your pool to bring the CYA down to 50ppm. And for all we know you could already be at 100 as store tests and test strips are notoriously unreliable at providing accurate and repeatable measurements.

You can always leave the trichlor pucks for when you are away, they do not expire as long as they are stored properly.

I strongly encourage you to read the Pool School, get a proper test kit Test Kits Compared and start adding liquid chlorine, aka bleach or liquid shock ASAP to bring the level up to 8-10ppm as per the Chlorine/CYA Chart. You can use Pool Math to determine how much liquid chlorine to add.